It (love) “rejoices not in iniquity;” common as this is, even among those who bear the name of Christ, who scruple not to rejoice over their enemy, when he falls either into affliction, or error, or sin. Indeed, how hardly can they avoid this, who are zealously attached to any party! How difficult is it for them not to be pleased with any fault which they discover in those of the opposite party–with any real or supposed blemish, either in their principles or practice!
What warm defender of any cause is clear of these? Yea, who is so calm as to be altogether free? Who does not rejoice when his adversary makes a false step, which he thinks will advantage his own cause? Only a man of love. He alone weeps over either the sin or folly of his enemy, takes no pleasure in hearing or repeating it, but rather desires that it may be forgotten for ever.
John Wesley (1748)