inexorable

It is for people whom we care nothing about that we demand happiness on any terms: with our friends, our lovers, our children, we are exacting and would rather see them suffer much than be happy in contemptible and estranging modes. If God is Love, He is, by definition, something more than mere kindness. And it appears, from all the records, that though He has often rebuked us and condemned us, He has never regarded us with contempt. He has paid us the intolerable compliment of loving us, in the deepest, most tragic, most inexorable sense.

cslewis