The Lord revealed to Joseph Smith that "And there are many kingdoms; for there is no space in the which there is no kingdom; and there is no kingdom in which there is no space, either a greater or a lesser kingdom. And unto every kingdom is given a law; and unto every law there are certain bounds also and conditions. All beings who abide not in those conditions are not justified" (D&C 88:37-39).
As members of the Church of Jesus Christ of Latter-day Saints, we are all familiar with the three degrees of heaven - celestial, terrestrial, and telestial. There is also one other that is not a kingdom of glory which is known as outer darkness, primarily because it exists outside the bounds of heaven and because those who dwell there literally live in utter darkness where there is no light at all.
Each of these four kingdoms take up space and there is no place where someone can go that is outside the boundaries of at least one of these four kingdoms. Therefore, there is no space found where there is no kingdom. The concern that many people have is knowing which kingdom they will inherit. The Lord explained that each of these four kingdoms have their own laws and those who live in a particular kingdom must obey the laws that govern that kingdom.
This is not so hard to understand because we see the same thing happening all around us. Those who live in the United States are required to live according to the laws which govern that country. Likewise, Mexico, which boarders America, also has a set of laws that govern their country but their laws are different from those of the United States. The same is true for those who live in Canada, or Saudi Arabia, or Iran, or Russia. In fact, every nation has their own set of laws which everyone living within their borders must obey. This applies to everyone, including those who come to visit from a foreign country.
In business, there are a multitude of companies yet each one has their own set of rules that their employees are expected to follow. While many of these rules may be the same for all companies, each company has their own set of regulations that are different from nearly all other businesses. Not all salesmen are paid the same way and not all employees receive the same wages. The opportunity and criteria for advancement are different from business to business, and the same is true of eternal kingdoms. Each kingdom is governed by its own set of laws, rules and regulations, and whichever kingdom someone lives in they are required to obey and follow the laws of that kingdom.
The Lord clarified this point when He said that he who is "not able to abide the law of a celestial kingdom cannot abide a celestial glory. And he who cannot abide the law of a terrestrial kingdom cannot abide a terrestrial glory. And he who cannot abide the law of a telestial kingdom cannot abide a telestial glory; therefore he is not meet for a kingdom of glory. Therefore he must abide a kingdom which is not a kingdom of glory" (D&C 88: 22-24).
In other words, those who are not willing to live by the laws that govern the celestial kingdom cannot live there. Violators are not put into some kind of prison but are required to go live somewhere else, outside the boundaries of the celestial kingdom. Since there is no space where there is not a kingdom, then it follows that if a person is not allowed to live in the celestial kingdom then they must go live in some other kingdom, and the kingdom they will go to is one whose laws they are able to live by.
Since the goal of all Christians is to live in heaven with God (i.e., the celestial kingdom) then it becomes important for us to know what its laws are so we can determine if we are qualified to live there.
Most Christians believe that the only law of heaven is to profess a sincere belief in Jesus Christ with little or no relationship to how we conduct our lives. However, members of the LDS Church believe that the requirement for living in the celestial kingdom is to keep God commandments. Since everything God does is for a good and wise purpose and since God wants us to live with Him in heaven then it is clear that the commandments God gives us is to prepare us to live with Him. Therefore, with this understanding it would seem that the laws of the celestial kingdom and the commandments of God are one and the same. However, while this is technically true, it does not convey the heart of the law that governs the place where God lives.
The law of the celestial kingdom can be summed up in the commandment to love God and love our fellow man. When boiled down to its pure essence that is what the law of the celestial kingdom is all about. It's no more complicated than that. If that is true, then it becomes essentially important for us to have a clear understanding of what that that means.
Christians talk about God being all powerful, and Latter-day Saints talk about the power and authority God possesses through His priesthood, but God revealed to Moses that his work and his glory is to bring to pass the immortality and eternal life of man (Moses1:9). God may have the power to control the universe and has the right to wield that power, but that is not what brings Him glory. His glory is derived from how many people He is able save.
Perhaps we can illustrate this by way of an example. Donald Trump is a self-made millionaire but it's not his money that brings him glory but the grand buildings that he has constructed, and the more buildings he erects and the more beautiful and stunning they are, the more glory Donald receives. Thus, his glory doesn't come from his position as the CEO of a large construction corporation or the amount of money he has made, but rather his glory comes from the things he has accomplished and his magnificent buildings are the evidence of his accomplishments.
In the same way, God's glory comes from the things that He accomplishes and what His work is all about is saving souls. Therefore, the more souls He can save the more glorious He becomes. The power and authority God has are only means to an end. Those are the tools He uses to increase His glory. Just as a farmer doesn't show off or brag about his shovel and hoe that he used to produce a fruitful garden, God doesn't brag about the power and authority of His priesthood. Instead, like the farmer who takes pride in how much fruit his garden has produced, God takes delight in how fruitful His efforts have been in saving His children. Although the amount of time, effort, and tools a farmer uses to produce a bounteous harvest are important, yet that's not what brings him joy. What matters most to the farmer is how much his garden has produced. In the same way, the only thing God is truly interested in is how successful the fruit of his labors have been in saving His children.
To love God means that we are willing to help Him achieve His goal, and since His goal is to save souls, and if we truly love God, then we will have the desire to make God's goal become ours. Therefore, when we love our neighbor as God loves them, we are also showing our love for God. This is what King Benjamin meant when he said "when ye are in the service of your fellow being ye are only in the service of your God" (Mosiah 2:17).
For this reason, the law of the celestial kingdom can be summed up in one word: service. This is why Jesus said, "Whosever will be great among you, let him by your minister" (Matthew 20:26). To minister to someone is to care about them and take care of their needs. Everything that is done in the celestial kingdom revolves around serving others. The reason why God is so great is because of the greatness of His service to others.
We generally don't think of God as serving people. Instead we usually think of us and the angels serving God, but when we look at God as our Father in heaven in the same way we look at fathers on earth, then the concept of service becomes clearer. The primary role of a father is to provide for the needs of their children. This not only includes a safe place for the children to live, with good food to eat and adequate clothing for them to wear, but the job of a father is to teach, help, guide, train, motivate, and encourage their children to grow up to be self-sustaining individuals who are capable of successfully surviving on their own. But, in order for a father (or mother) to fulfill this role, they have to serve the needs of their children.
In the same way, God, our Father in heaven, is serving His children by doing everything possible to help them become exalted. Those who live in heaven with God are likewise doing all in their power to serve in assisting Him to fulfill His work. This is why the celestial kingdom is all about service, to God and to our fellow beings. The purpose of all the commandments and the purpose of all the callings we have in the Church is to help prepare us to live a life of service in heaven. However, the acts of service we perform here on earth pales in comparison to the kind of service that is required of those who live in the celestial kingdom. No matter how much service we might perform here on earth, it is just a small taste of what awaits us in heaven. In that glorious realm, the work of service is done on a far greater and a more glorious scale. If we find it difficult to serve others in this life, we will be completely unprepared to take on the greater work that is required of those who dwell in the celestial kingdom.
We see people in the LDS Church who come every Sunday but who do not want to accept a calling. They come to be spiritually fed but they do not come to serve. As such, after the resurrection, they will find themselves unable to perform the kind of service that celestial people are required to perform. Therefore, if they cannot abide or live by the law of the celestial kingdom, of necessity, they must go live in a different kingdom.
In the LDS Church it is generally taught that to make it to the celestial kingdom a person has to keep all the commandments of God and much has been said about the need for us to behave in a Christ-like manner, meaning that that we should strive to behave as Christ did by being patient, kind, slow to anger, and living a chaste, honest, and virtuous life. A lot has also been said about repenting of our sins and not committing them again.
The scriptures tell us that God cannot look upon sin with the least degree of allowance and so it is believed that in order to qualify to live in the celestial kingdom a person must live as sinless a life as they can and where we fall short, Christ's atonement will make up the difference. We refer to this process as living a righteous life.
However, the more righteous someone becomes as they strive to be more patient, chaste, and honest, as well as repenting of their sins, what happens as a result of this effort is that they gain a greater desire to serve others. And the opposite is just as true. The less righteous a person becomes the less likely they are to want to serve others. Therefore, there is a direct correlation between righteousness and service. A person who truly loves God and strives to live a Christ-centered life, will find themselves automatically desiring to serve others.
But what about those who don't belong to the LDS Church but whose hearts are filled with love and compassion for others? There are many such people who serve others with a willing heart and who seek to bring people to a saving knowledge of Christ. If the law of the celestial kingdom is all about service then shouldn't anyone who wants to serve God and serve others be allowed to live with God regardless of which denomination they belong to?
The answer is no because living in the celestial kingdom requires more than just having a desire to serve others, even if they are doing it out of love for Christ. To be a member of the celestial kingdom a person must be a member of Christ's church, which involves being baptized by someone having the proper power and authority and then being faithful in building up Christ's true kingdom rather than building up someone else's kingdom.
There will be those who feel that if the law of the celestial kingdom is all about service, then it would seem unfair for God to exclude believers in Christ from living with Him if they have a desire to serve Him. To understand why this won't work we can look at Donald Trump again as an example. Suppose there was a person who truly admired Mr. Trump for his many accomplishments and bought every book he ever wrote on how to become successful, studied the material, and then truly tried to follow his advice. This person might even have traveled to witness for themselves the many beautiful buildings Trump constructed and glowingly talked to everyone they met about the greatness of Mr. Trump.
Yet, despite all of this, Donald Trump would not pay this person one penny if they were not part of his organization. However, Mr. Trump would pay a salary to everyone who worked for him, including a janitor who had no knowledge of construction, nor any ambition to become wealthy. But those who work hard to help Trump's business succeed could find themselves advancing in power, prestige, and money within the company. Although a person outside of Trump's organization might also increase their wealth and power by following Donald's strategy, their money would not come from Trump but from some other source.
If we want what God has to offer then we must be part of His church, and the more we serve Him in building up His kingdom, rather than the kingdom established by someone else, the more we will receive from Him. The reason why is because the work of salvation that Christ has started here on the earth is not meant to end after the resurrection but will continue to grow throughout the eternities. In other words, the work of salvation will never end. After the resurrection, it will move to a higher and more exalted level where the need for service will become much greater there than it is here on earth. Those who are not willing to help Christ build up His church during their time in mortality will certainly not be able to help Him build His church in the eternities.
Those Christians who belong to other faiths may feel they are working for Christ but in reality they are working for a different company. Lutherans, Methodists, Episcopalians, Catholics, Presbyterians, and even non-denominationalists all love Christ and revere the book written by Him. They have intently studied its teachings and have sincerely tried to apply those teachings in their life and in many cases have even seen success in becoming a better Christ-like person, but they are not working to build up Christ's kingdom. Instead, they are working to build up someone else's church. As such, their eternal reward will not come Christ but from those whom they have chosen to work for.
It is the common belief among nearly all Christians that it doesn't matter which church a person belongs to as long as they accept Christ as their personal Savior. But the truth is that unless a person has joined themselves to Christ's true church through baptism, they are working hard at building up someone else's church.
This very situation existed in the days of the earliest Christians. To the churches in Galatia Paul lamented "I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed" (Galatians 1:6-8).
In Paul's day, among the believers in Christ, there were Christians who taught a different gospel than that which Paul taught. Paul condemned these divisions of doctrine, showing that not all interpretations of salvation are equally valid. There is only one gospel of Christ and only those who belong to the church that teaches the correct doctrines of salvation are following the path that leads to the celestial kingdom.
To the Corinthians Paul wrote, "Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment. For it hath been declared unto me of you, my brethren, by them which are of the house of Chloe, that there are contentions among you. Now this I say, that every one of you saith, I am of Paul; and I of Apollos; and I of Cephas; and I of Christ. Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul?" (1 Corinthians 1: 10-13).
This could easily be rewritten today to read, "I beseech you my fellow Christians that you all speak the same thing and that there be no differences among you concerning the doctrine of Christ. You should be perfectly joined together, having the same mind. But instead, one says, I am a Lutheran, another says, I am a Catholic, and another says, I am a Methodist. Is Christ divided? Was Luther crucified for you? Were you baptized in the name of John Wesley or the Presbyterian faith?"
There is only one kingdom of God and only those who are willing to join and help build up that kingdom are entitled to the reward God gives to those who serve Him. Those who build up another kingdom must seek their reward from those whom they serve. Therefore, eternal salvation comes only to those who not only belong to Christ's true church but have shown a willingness to serve Him faithfully because that's what they will be doing forever when they inherit the celestial kingdom.