The scriptures are full of God’s promises to us, His children. "And so, after he had patiently endured, he obtained the promise." Hebrews 6:15 These promises aren't one way, they are covenants. If you do that, then this is the reward. Earth life is a testing ground full of trials to be enduring and tests to pass with beautiful promises attached. "I, the Lord, am bound when ye do what I say; but when ye do not what I say, ye have no promise." D&C 82:10
"The way of the gospel is a simple way. Some of the requirements may appear to you as elementary and unnecessary. Do not spurn them, humble yourselves, and walk in obedience. I promise that the results that follow will be marvelous to behold and satisfying to experience." Gordon B. Hinckley, Stand a Little Taller, 49
When we faithfully strive to obey His commandments, devote our lives to His kingdom, and live by His will, we will be happy, blessed, a receive a crown of righteousness. That doesn't mean earth life will be a bed of roses but that we will understand the process and find joy in it. Additionally, eternal rest in the presence of my Heavenly Father, Savior, Jesus, and dear departed loved ones sound pretty wonderful, too.
"Obedience to His commandments and a commitment to living a life that demonstrates He can trust you...character is woven patiently from the threads of doctrine, principle, and obedience." Richard G. Scott, Ensign, January 2007, 10.