2 For unity and peace and concord afford the greatest pleasure not only to men who believe and know the truth, but also to heavenly angels themselves, to whom the divine word says it is a joy when one sinner repents and returns to the bond of unity. But assuredly this would not be said of the angels, who have their conversation in heaven, unless they themselves also were united to us, who rejoice at our unity; even as, on the other hand, they are assuredly saddened when they see the diverse minds and the divided wills of some, as if not only they do not together invoke one and the same God, but as if, separated and divided from one another, they can neither have a common conversation nor discourse. Except that we may in this matter give thanks to Stephen, that it has now happened through his unkindness that we receive the proof of your faith and wisdom.
But although we have received the favour of this benefit on account of Stephen, certainly Stephen has not done anything deserving of kindness and thanks. For neither can Judas be thought worthy by his perfidy and treachery wherewith he wickedly dealt concerning the Saviour, as though he had been the cause of such great advantages, that through him the world and the people of the Gentiles were delivered by the Lord's passion.
Source: The Epistles of Cyprian (New Advent)