Leo the Great, a native of Tuscany, was elected bishop of Rome in 440 and is perhaps best known for meeting with Attila the Hun in 452 and persuading him to turn back from his invasion of Italy.  The nearly 100 sermons and 150 letters of his that have survived are mostly concerned with theological questions concerning the person of Jesus Christ and his role as Mediator and Saviour.  Leo taught extensively on Christ's presence in the Church: in the teaching of Scripture, in the preaching of the faith, in the liturgy and in the life of the individual believer.

Since it is by giving alms that everything is pure for you, you will also receive that blessing which is promised next by the Lord: Blessed are the pure of heart, for they shall see God. Dear friends, great is the happiness of those for whom such a reward is prepared. Who are the clean of heart if not those who strive for those virtues we have mentioned above?