The Book of Mormon states that “if ye have no hope ye must needs be in despair; and despair cometh because of iniquity” (Moroni 10:22). Mormons think that when people stop believing God and start believing Satan, the Great Deceiver, they despair.
Since a lack of hope is the cause of despair, hope is crucial for the cure. God repeatedly counsels us to “be of good cheer” (John 16:33, Acts 27:22), and to hope and rejoice. So where does a person obtain hope?
Mormon theology teaches that faith and hope cannot be separated. Second Corinthians 4:8 says that while the saints may be perplexed, they need not experience despair, so they know that faith in the gospel gives hope. That hope is maintained by obeying the commandments and acting in righteousness, which is an exercise of their faith and prevents iniquity. They believe that when they do their best they have a clear conscience and are happy, cheerful, and optimistic.
But they believe that a deep understanding of the gospel plan also helps. Mormons look at things from an eternal perspective, not just from their time on earth, often painful and unsatisfying, and so they receive not only hope but comfort. With that, they realize that “This, too, shall pass,” “With God, all things are possible” (Matt. 19:26) (including enduring many difficult adversities), and “All things work together for good to them that love God” (Rom 8:28). They know that torment or unhappiness is temporary and better times are ahead. They know that they can make it, though they sometimes fail. They know they're forgiven when they repent. And they know that, through Christ's Atonement, they can be saved. Paul pointed to their “hope of eternal life, which God, that cannot lie, promised before the world began” (Tit. 1:2). So they trust that there is reason and purpose in what may seem at times like a senseless and unfeeling universe. They know, through their pursuit of an active, vibrant relationship with their Father in Heaven and their Savior, that they are loved and valued. Their hope is always centered in Christ. They believe not only in His existence and glory, but they believe His promises--and His intention and power to fulfill them.
Mormons also believe that the Holy Ghost, who bears witness of Christ and His Atonement, will not allow them to suffer despair if they remain worthy of his presence. Paul testifies that they “may abound in hope, through the power of the Holy Ghost” (Rom. 15:13). The Holy Ghost wields a power that warms, lifts, and comforts them when they feel downhearted, wretched, needy, or abandoned. He reminds them of God's love and devotion for them. He reminds them that everything created, materially and spiritually, has been for their benefit, that their Heavenly Father's concerns for them and all others launched the entire gospel plan: the creation of the earth for their enjoyment and benefit, prophets to counsel and guide them, and most of all, our Savior who suffered and died for them. The Holy Ghost abides with them in times that try their faith and souls. In the valley of deepest depression, when they can see nothing but blackness, no bottom, no top, and no sides, he pulls them out and lifts them to the light. He helps them see that never, in the deepest recesses of their Father's heart, can they find negligence or lack of concern for them. they learn with keener understanding that he will never throw them away; they can only walk away from him. Understanding this, they do not despair. They hope.