Adam and Eve disobey God's command not to eat fruit from the tree of good and evil. The result of this was separation from God and the introduction of death into the world.
God's gift to human beings of the freedom and ability to choose what to do. Humans should make choices that God would approve of otherwise they will separate themselves from God.
The teachings of Jesus during the Sermon on the Mount in which he describes the actions and attitudes that should characterize Christians and by which one can discover genuine meaning and happiness.