The Path of Moral Progress
These reflections from C. H. Dodd on Paul's theology seem to me to be close to the heart of Wesleyan theology. As with justification, what we often call "sanctification" (conformity to the image of Christ) is also by grace through faith.
I cannot verify this quote, since I do not actually own this book. I found this quote from a reliable Internet source many years ago.
The higher faiths call their followers to strenuous moral effort. Such effort is likely to be arduous and painful in proportion to the height of the ideal, desperate in proportion to the sensitiveness of the conscience. A morbid scrupulousness besets the morally serious soul. It is anxious and troubled, afraid of evil, haunted by the memory of failure. The best of the Pharisees tended in this direction, and no less the best of the Stoics. And so little has Christianity been understood that the popular idea of a serious Christian is modeled upon the same type of character.The ascetic believed that, because he was so holy, the Devil was permitted special liberties with him, and he found in his increasing agony of effort a token of divine approval.
Not along this track lies the path of moral progress.
Christianity says: face the evil once for all, and disown it. Then quiet the spirit in the presence of God. Let His perfections fill the field of vision. In particular, let the concrete embodiment of the goodness of God in Christ attract and absorb the gaze of the soul. Here is the righteousness, not as a fixed and abstract ideal, but in a living human person. The righteousness of Christ is a real achievement of God's own Spirit in man.
— C. H. Dodd, The Meaning of Paul for Today