This only refers to the "Advice to Young Converts" letter written to a young Christian woman requesting pastoral advice:
This has been my first formal exposure to Jonathan Edwards writing and it was great. The letter is loaded with excellent advice for Christian life - whether young convert or old, clarified into nineteen separate points, twelve of which I underlined or otherwise noted for myself in the margins as I was reading.
Though written in the mid-1700s, the advice is timeless, and lessons I have come to appreciate such as: "When you hear sermons, hear them for yourself" (third point). The fifteenth point is the first clear and practical advice I have read about Christian fasting - when, why and how you might do it - with an important emphasis on it being done in secret with prayer.