A.W. Tozer emphasizes the concept of 'exchange' in the Christian experience, particularly through the lens of Isaiah 40:31, where waiting on the Lord leads to an exchange of strength. He highlights the foundational principle of vicarious atonement, where sinners can exchange their guilt for Christ's righteousness, a truth often overlooked by the wise of this world. Tozer explains that this exchange continues throughout the Christian life, transforming wrath into acceptance and condemnation into grace, illustrating the profound changes that occur when one embraces faith in Christ. Ultimately, he asserts that this divine exchange is a simple yet powerful aspect of the believer's journey.

A great preacher whom I heard a few years ago said that the word "renew" in Isaiah 40:31 really meant "exchange"; so the text should read, "They that wait upon the Lord shall exchange their strength." Oddly enough I do not now remember how he developed his sermon or just how he applied the text, but I have been thinking lately that the man had hit upon a very important idea; namely, that a large part of Christian experience consists of exchanging something worse for something better, a blessed and delightful bargain indeed. At the foundation of the Christian life lies vicarious atonement, which in essence is a transfer of guilt from the sinner to the Saviour. I well know how vigorously this idea is attacked by non-Christians, but I also know that the wise of this world in their pride often miss the treasures which the simple-hearted find on their knees; and I also remember the words of the apostle; "He hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him" (2 Cor. 5:21). This is too plain to miss for anyone who is not willfully blind: Christ by His death on the cross made it possible for the sinner to exchange his sin for Christ's righteousness. It's that simple. No one is compelled to accept it, but at least that is what it means. And that is only the beginning. Almost everything thereafter is an exchange of the worse for the better. Next after the exchange of sin for righteousness is that of wrath for acceptance. Today the wrath of God abides upon a sinning and impenitent man; tomorrow God's smile rests upon him. He is the same man, but not quite, for he is now a new man in Christ Jesus. By penitence and faith he has exchanged the place of condemnation for the Father's house. He was rejected in himself but is now accepted in the Beloved, and this not by human means but by an act of divine grace.