From James 1:13-15

"Let no one say when he is tempted, “I am being tempted by God,” for God cannot be tempted with evil, and he himself tempts no one. But each person is tempted when he is lured and enticed by his own desire. Then desire when it has conceived gives birth to sin, and sin when it is fully grown brings forth death."

The ultimate aim of our sinful nature is suicide, a wicked undoing of God's creation for the person. This is a universal fact of the flesh, an impulse to self destruction. When someone commits suicide, they are just being more direct than the more roundabout way people do it.