“The concept of substitution may be said . . . 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 where only man deserves to be. Man claims prerogatives which belong to God alone; God accept penalties which belong to man alone.” --John R.W. Stott, The Cross of Christ (InterVarsity Press, 1986) “All our obedience, every resolve to do good, and every work of faith is ‘by his power’ and so that the Lord Jesus would be glorified because of the grace he gives. Yes, we must pursue obedience, but that obedience must always be cruciform, formed by Christ’s cross . We must seek to obey because of the cross, find the grace to obey because of the cross, and live free from condemnation whether we succeed or fail in the light of the cross....