I've read this little article many times over the last twenty years or so. I think it's well worth sharing: "Letter on Free-will". I think his first paragraph is striking:
This fresh breaking out of the doctrine of free-will helps on the doctrine of the natural man's pretension not to be entirely lost, for that is really what it amounts to. All men who have never been deeply convinced of sin, all persons with whom this conviction is based upon gross and outward sins, believe more or less in free-will. You know that it is the dogma of the Wesleyans, of all reasoners, of all philosophers. But this idea completely changes all the idea of Christianity and entirely perverts it.