Thomas Doolittle (1632-1707), a Puritan and tutor of Matthew Henry, was a non-conformist minister in England when such a stance meant suffering and persecution at the hands of the government.
Doolittle's Treatise Concerning the Lord's Supper is a typically masterful work by a spiritual doctor. He not only examines our hearts for preparation for the Supper, but also what we will gain spiritually through communion with Christ, and what will hinder that communion.
He also has three "Dialogues" in which he addresses the needs of every kind of participant, those burdened with sin...