BELIEVING in God means only pleasing him and living according to his word. Accept that God sent his son to die for us and that if we follow the orders and statutes.
If we believe all this, we will be at rest, because believing does not mean that one feels or understands that it is so. Believing means that we build and guide our lives in the word of God, trusting that he will guide and reward us, because he has said so!
Hebrews 11: 6 "But without faith it is impossible to please God; for it is necessary that he who comes to God believe that there is, and that he is a rewarder of those who seek him"
He who wants to please men will never have rest, but he who believes in God will be the rewarder of those who seek Him.