“Nothing is stable in the realm of power, and even closest of friends can be transformed into the worst of enemies.”

1950s, Loving Your Enemies (Christmas 1957)
Context: A third reason why we should love our enemies is that love is the only force capable of transforming an enemy into a friend. We never get rid of an enemy by meeting hate with hate; we get rid of an enemy by getting rid of enmity. By its very nature, love creates and builds up. Love transforms with redemptive power.

1950s, Loving Your Enemies (Christmas 1957)

Source: A Breath of Snow and Ashes

Variant: A friend is nothing but a known enemy.

Ch 6
The Rahotep series, Book 2: Tutankhamun

1950s, Loving Your Enemies (November 1957)
Context: Now there is a final reason I think that Jesus says, "Love your enemies." It is this: that love has within it a redemptive power. And there is a power there that eventually transforms individuals. That’s why Jesus says, "Love your enemies." Because if you hate your enemies, you have no way to redeem and to transform your enemies. But if you love your enemies, you will discover that at the very root of love is the power of redemption. You just keep loving people and keep loving them, even though they’re mistreating you. Here’s the person who is a neighbor, and this person is doing something wrong to you and all of that. Just keep being friendly to that person. Keep loving them. Don’t do anything to embarrass them. Just keep loving them, and they can’t stand it too long. Oh, they react in many ways in the beginning. They react with bitterness because they’re mad because you love them like that. They react with guilt feelings, and sometimes they’ll hate you a little more at that transition period, but just keep loving them. And by the power of your love they will break down under the load. That’s love, you see. It is redemptive, and this is why Jesus says love. There’s something about love that builds up and is creative. There is something about hate that tears down and is destructive. So love your enemies.