An Epistolary Discourse Proving, from the Scriptures and the First Fathers, that the Soul is a Principle Naturally Mortal; But Immortalized Actually by the Pleasure of God, to Punishment; Or, to Reward, by Its Union with the Divine Baptismal Spirit. Wherein is Proved, that None Have the Power of Giving this Divine Immortalizing Spirit, Since the Apostles, But Only the Bishops