Remember the ex-slave-trader who wrote Amazing Grace? John Newton was an Anglican priest who preached just about to the day he died in 1807. I wish his letters were as well known as his hymns; they're packed with spiritual insight, pastoral wisdom, and sound, generous Reformed theology. Here's a sample:
"Regeneration, or that great change without which man cannot see the kingdom of God, is the effect of Almighty power. Neither education, endeavors, nor arguments, can open the eyes of the blind. It is God alone, who first caused light to shine out of darkness, who can shine into our hearts, 'to give the light of the knowledge of the glory of God in the face of Jesus Christ' (2 Cor 4.6). People may attain some natural ideas of spiritual things by reading books, or hearing sermons, and may thereby become wise in their own conceits; they may learn to imitate the language of an experienced Christian; but they know not what they say, nor whereof they affirm, and are as distant from the true meaning of the terms, as a blind man, who pronounces the words 'blue' or 'red,' is from the ideas which those words raise in the mind of a person who can distinguish colors by sight. And from hence we may infer the sovereignty, as well as the efficacy, of grace ... From hence likewise we may observe the proper use and value of the preaching of the Gospel, which is the great instrument by which the Holy Spirit opens the blind eyes. Like the rod of Moses, it owes all its efficacy to the appointment and promise of God. Ministers cannot be too earnest in the discharge of their office; it behooves them to use all diligence to find out acceptable words, and to proclaim the whole counsel of God. Yet when they have done all, they have done nothing, unless their word is accompanied to the heart by the power and demonstration of the Spirit."