Pain is good, I'd say, when it's incidental to Love. In 'I give up my life for my friend' it is my friend, not my death, that matters. And sometimes I needn't give up my life for him, I can live for him, and with him, and the power of the spirit is then equally manifested, I should think.
Letter 285, to George Thomson, 1 August 1931 - Selected Letters (1985)