The dread Mysteries, full of such great salvation, which are celebrated at every Liturgy, are also called a Thanksgiving [Eucharistia] because they are the remembrance of many benefits, and they signify the culmination of God's Providence towards us, and in every way cause us to be thankful to Him.
What is it that commends our own life? Is it miracles, or is it a life scrupulously and uprightly lived? It is rather from the latter that miracles arise, and to that they tend. For he that lives a worthy life, draws this grace upon himself; and whosoever receives such graces receives them that he may help others to amend their lives. For even Christ wrought miracles that He might the more be accepted as worthy of belief, and so might the more attract men to Himself, and by this means bring sanctity into their lives.