From another thread:
If I, then, were to ask, What is it to love our neighbor? the answer would be, The love of God causes us to love Him more than our wealth, our health, our good name, and even our life, and the love which we should have for our neighbor should enable us to love him as ourselves, so that all the good that we should wish for ourselves, we should wish for him. We must have this charity without which there is no heaven to hope for, and no friendship with God. Now, what do we understand by the word, our neighbor? Nothing is easier of comprehension. Every one of our brother men, even those who have wronged us, who have injured our good name, and calumniated us, or who have even sought to take our life. We ought to love them as we love ourselves, and wish them all the good that we wish ourselves. It is not only forbidden for us to wish them ill, but we must also render them service if they require it of us, and we are able to do so. We ought to rejoice when our enemies are successful in business, and we should feel sorry when they meet with reverses or losses, and we must take their part when others speak bad of them. We should tell others the good we know of them, and not avoid their society. Behold, my dear friends, this is how God wills that we should love our neighbor. If we do not believe this, then we must admit that we neither love our neighbor nor do we love God. We are bad Christians, and we shall be lost!