Joy comes from value. Value comes from suffering. Because God desires for each of us to obtain as much joy as we are willing to receive, we are required to suffer, but this suffering is very different than the suffering of the wicked. Joy is preceded by the suffering required to obtain and live according to the knowledge and character of God.
Faith is central to the mechanism for obtaining greater joy in at least two ways. First, faith helps a person walk into a path of greater suffering in order to obtain greater joy. Joy comes from learning and living according to beliefs that produce it. However, the greater the joy, the less obvious the way, because discovering and walking paths that lead to greater joy causes greater suffering. Only faith will prove sufficient to help you endure what must be endured to encounter the joy that lies on the other side of the willful suffering that permeates the life of the righteous. Only faith will enable you to do what is required for you to encounter the greatest joy. Through faith, you will do harder things, endure longer paths, and suffer more than you would without faith:
Know ye that ye must come to the knowledge of your fathers, and repent of all your sins and iniquities, and believe in Jesus Christ, that he is the Son of God, and that he was slain by the Jews, and by the power of the Father he hath risen again, whereby he hath gained the victory over the grave; and also in him is the sting of death swallowed up. (Mormon 7:5)
As you subject yourself to affliction through your faith in Christ, you will enable God to lead you to greater outcomes and to teach you what you can understand in no other way.
A person can’t be saved in ignorance. “It is impossible for a man to be saved in ignorance.” (D&C 131:6) Rather, as one becomes a disciple of Christ, their life transforms into a school where God teaches them, little by little, more about how he is and about how the world is.
As you develop and retain complete trust in God and exercise complete obedience to him, he will teach you what you need to know to be capable of experiencing complete and continuous happiness in spite of the depth and breadth of suffering in this world:
And moreover, I would desire that ye should consider on the blessed and happy state of those that keep the commandments of God. For behold, they are blessed in all things, both temporal and spiritual; and if they hold out faithful to the end they are received into heaven, that thereby they may dwell with God in a state of never-ending happiness. O remember, remember that these things are true; for the Lord God hath spoken it. (Mosiah 2:41)
In so doing, he will prepare you to continue to be this way forever after this life, when all people will be eternally exposed to things as they really are—a degree of knowledge containing far more pain and sorrow than the uninitiated can endure in this life (see D&C 19:1-22).
Power is required to endure that level of pain and suffering. Faith, hope, and charity are tied together as corequisites to enduring in acting according to your understanding of God’s character as he continuously reveals more of himself and more about reality to you.
Enduring all things here causes you to gain the unspeakable power of God that can be felt, but not spoken, by those who can sense the burdens you have carried, even if they can’t see them:
25 ...none other power can operate against them— 26 And this because of their exceeding faith, and their patience in their tribulations—(Alma 60)
Endurance can only come through faith and it is through faith that a person endures what is required to learn about and become like God. Through repeatedly receiving more information about God from others, evaluating what they’ve heard through reason, and implementing the elements that have support, a person will gain more and more knowledge of and trust in God and will acquire his character and attributes.