August Hermann Francke (1663-1727), German Lutheran who carried on the torch of Pietism in Spener's wake, on the new birth:
"Nor is it enough to explain that first and mighty Change, which is at once made in a Sinner at his Conversion, when he comes to love that God which before he hated, and to hate the Evil which he before loved; when from being an Unbeliever he becomes a Believer; or when his false and dead Faith is changed into a true and saving one: But that further progressive Change should also be much recommended, in which the Christian must be improving to the very End of his Life."
--Dale Brown, Understanding Pietism (Grand Rapids: Eerdmans, 1978), 96.
"[N]o doctrine in Christianity is more necessary than the doctrine of rebirth. This is the very ground upon which Christianity stands. A person without this is not to be called a Christian. Just as the article of creation is the first, without which the others would not be (for if man were not created, how could his redemption and sanctification occur?), so if the person is not created anew or born of God, it does not help at all that Christ died for him; nor does it help at all that he has sent the Holy Spirit, and so forth. But when new birth occurs, we enjoy all the more the heavenly Father, our Savior, and the dear Holy Spirit."
--God’s Glory, Neighbor’s Good: A Brief Introduction to the Life and Writings of August Hermann Francke (Chicago: Covenant, 1982), 135, 142.