Posted by J.D. Greear, author of the book Breaking the Islam Code: Understanding the Soul Questions of Every Muslim (2010):
There are multiple things that Christ accomplished for us when he died on the cross. He "paid" our sin debt (Romans 3:25-26), "cleansed us" from defilement (1 John 1:9), defeated the powers of darkness (Colossians 2:15), reversed the curse of death (Galatians 3:13), gave us a model for how to love others and overcome injustice (1 Peter 2:21), and demonstrated to us how much God loves us (Romans 5:8), just to name a few. Theologians call these the "theories of the atonement."
In recent years, the 1st of those, the penal substitution "theory of the atonement" (the idea that Christ satisfied the wrath of God by taking upon Himself the penalty for our sin, thus paying our sin debt) has fallen out of favor with more sophisticated theologians (read: liberal and some 'emerging'; also on popular books like The Shack). They believe that "penal substitution" is based on a Westernized justice theory that modern man has progressed beyond. God does not demand that justice be served in forgiving our sins, they say, so Christ didn't have to die to pay any sin debt. He was stopping the curse of death, demonstrating His love for us, and defeating Satan. To believe that Jesus died to pay a debt to God's justice, they say, makes God sound barbaric and guilty of cosmic child abuse (demanding Christ die so that He could forgive). Ironically, this is exactly what Muslims say.
This, of course, goes directly against the teaching of passages like Romans 3:25-26 and Isaiah 53:5-6. And, as Jim Belcher points out in his book Deep Church [my favorite book of 2009], "penal substitution" is ultimately the basis for all the other "theories of the atonement." They are only true because Christ died for our sins.
The penal model forms the foundation of the Christus Victor model (Christ’s victory over the principalities and powers at the cross). Christ's victory is gained... through penal suffering.’ (How can victory be gained if sin is not first atoned for? How can we start to live in the kingdom if our sins are not first forgiven and we are given new power to live in the service of and obedience to the kingdom?) (p. 116)
I think this is a great paragraph... How did Jesus defeat the powers of sin and death? By paying for our sin. How did He ransom us? By paying our sin debt. How did He stop the curse? By satisfying it in our place. Why was His death a demonstration of love? Because He paid a debt we could never pay.
This point is one I also try to make in my new book Breaking the Islam Code. In that book, I suggest that presenting the death of Christ in terms of cleansing, rather than forgiveness, is better when sharing Christ with Muslims. Muslims are reminded every time they wash and pray of their defilement before God, and presenting to them that Jesus' blood can wash their hearts clean resonates with them more immediately than does the idea that Jesus' paid a sin-debt). That does not imply, however, that "cleansing" is in contrast to, or eclipses, "penal substitution," because the reason Jesus' blood cleanses us from sin is because Jesus paid our sin debt. If you won't think me too egotistical, I'd like to quote myself...
I want to be careful implying that cleansing and forgiveness are two fundamentally different things. They are not. When 1 John 1:9 says that we are “cleansed” to have fellowship with the Father, this happens by the faithful and just forgiving of our unrighteousness. It is because Jesus paid our sin debt that we can be cleansed and have fellowship with God again. What I am saying is that emphasizing that we are cleansed, and that we can through this cleansing stand in God’s presence again, has more appeal to the Muslim than simply saying that Jesus settled our outstanding accounts at the register of God’s justice.