The Difference between Justification and Sanctification

Tony Lane:

The Reformation doctrine makes a deliberate and systematic distinction between justification on the one hand and sanctification or regeneration on the other hand.

• Justification refers to my status; sanctification to my state.
• Justification is about God's attitude to me changing; sanctification is about God changing me.
• Justification is about how God looks on me; sanctification is about what he does in me.
• Justification is about Christ dying for my sins on the cross; sanctification is about Christ at work in me by the Holy Spirit changing my life.

The Reformers were careful to distinguish these two--but not to separate them. One cannot have one without the other--as with the heat and light of the sun. The sun gives out heat and light. These two cannot be separated. When the sun shines there is both heat and light; yet they are distinct and not to be confused. We are not warmed by the sun's light nor illumined by its heat. To use a modern illustration, justification and sanctification are like the two legs of a pair of trousers, not like two socks which may well become separated and, in the author's experience, too often do become separated.

Anthony N.S. Lane, Justification by Faith in Catholic-Protestant Dialogue: An Evangelical Assessment, p. 18.