The coming of Our Lord Jesus Christ and the revelation of the commandment of love profoundly transformed human relationships. Until then, justice was limited to the rigour of the law of retaliation: “An eye for an eye and a tooth for a tooth” (Ex 21:24). By uttering the divine words: “Do good to those who hate you” (Mt 5:44), the Master elevated human coexistence to an unprecedented level, transcending mere reciprocity.

Considering this, it appears more meritorious to love an enemy than a friend. Daily experience attests to the difficulty of this task… Our Lord himself asks: “Love your enemies […]. For if you love those who love you, what reward have you?” (Mt 5:44, 46). Accordingly, it would seem logical to infer that what requires greater effort is also more meritorious.

In an article dedicated to this topic (cf. Summa Theologiæ, II-II, q.27, a.7), Aquinas poses the inverse question: what would be worse, to hate a friend or an enemy? The answer leaves no room for doubt: to hate a friend, who is closest to us and loves us, constitutes a much more serious fault. By symmetry, the Common Doctor concludes with all simplicity: “It is better to love the best,” for the friend who loves us is better than the enemy who hates us, and what is better is necessarily more meritorious.

Someone might object that love for friends can often be tainted by egoism, self-interest, hedonism, etc., whereas love for one’s enemy requires love for God as its motive. The Angelic Doctor concedes that this objection is well-founded, adding that love for God is revealed more intensely when it expands the human heart to embrace distant objects, such as enemies, “just as the power of fire manifests itself all the stronger the farther it spreads its heat.” This capacity for extension obviously calls for more “fuel,” which is none other than the virtue of charity.

Aquinas further inquires: and what about love for a friend grounded on love for God? Returning to the same metaphor, he observes that fire acts with more vigour on what is closer than on what is distant. Analogously, true charity makes us love those closest to us with greater fervour. Such love is not only more ardent, but it is also more meritorious, for it has God Himself as its cause – and not mere human affection.

For these reasons, St. Thomas Aquinas offers us a valuable lesson: love for friends, when restricted to mere companionship, lacks supernatural merit. However, if we love our neighbour with true charity, we will not only attain the fullness of God’s grace – “charity, which is the bond of perfection” (Col 3:14) – but we will also be worthy heirs of the first Christians, the object of exclamation even from pagans: “See how they love one another!” (Tertullian, Apologeticum, ch. XXXIX, n. 7).