When a Christian sins and engages in the deeds of darkness, it’s as if he has had a relapse.
Imagine yourself lost in a cave. As you attempt to find your way out, you only proceed deeper and deeper into the network of tunnels. Soon you’re in the belly of the earth. You’re scared. Your heart is pounding. Your eyes are wide open, but all you can see is an oppressive blackness. You grope for hours, and the hours become a day, and then another day. All hope seems lost. Suddenly, off in the distance, there is a pinpoint of light. You move toward it, groping lest you fall into a deeper pit. Finally the light begins to widen and you find yourself at an opening in the cave! With your remaining strength you charge out into the daylight. You then know a freedom like nothing you had ever conceived was possible. However, not long after your escape you decide there were several things you enjoyed in the cave. So you go back in. How foolish! Yet that is essentially what a Christian does when he follows after deeds of darkness.
MacArthur, John: Truth for Today : A Daily Touch of God’s Grace. Nashville, Tenn. : J. Countryman, 2001, S. 196