Quote from Calvin: Love of Neighbour

Assuredly there is but one way in which to achieve what is not merely difficult but utterly against human nature: to love those who hate us, to repay their evil deeds with benefits, to return blessings for reproaches. It is that we remember not to consider men's evil intention but to look upon the image of God in them, which cancels and effaces their transgressions, and with its beauty and dignity allures us to love and embrace them.
(Institutes III.vii.6, Battles translation)