This choice lead to the fall (sin). Sin is disobedience to God. This decision caused spiritual separation from God and physical death. Separation occurred because God is perfect and holy. His holiness cannot dwell with sin and His justice cannot allow it to go unpunished.
As a result of sin, the natural world was also cursed and began to die. The ground became less fertile and man had to work harder to harvest much less. Also, human relationships were no longer harmonious; cruelty, hatred, and murder were introduced into a world originally created for love.
Man continues to sin. Because of our sinfulness, man cannot know and experience God's love and fellowship no matter how hard he may try.
"There is no one righteous, not even one; there is no one who understands, no one who seeks God" (Romans 3:10,11) "for all have sinned and fall short of the glory of God" (Romans 3:23). And, "the wages of sin is death" (Romans 6:23).