Satisfaction and Substitution
"The theological words satisfaction and substitution need to be carefully defined and safeguarded, but they cannot in any circumstances be given up. The biblical gospel of atonement is of God satisfying himself by substituting himself for us.
"The concept of substitution may be said, then, to lie at the heart of both sin and salvation. For the essence of sin is man substituting himself for God, while the essence of salvation is God substituting himself for man. Man asserts himself against God and puts himself where only God deserves to be; God sacrifices himself for man and puts himself were only man deserves to be. Man claims prerogatives that belong to God alone; God accepts penalties that belong to man alone." (John R.W. Stott, The Cross of Christ, p. 159)