One of Our Great Sins

At the end of a January 1940 letter to Dom Bede Griffiths, C. S. Leis remarked--

I agree with you very strongly about the necessity of trying as hard as we can to obey the apostolic 'Rejoice always': and I think we sin by needless neglect of this as often as by anything else. The attempt to obey it is at present one of my three morning resolutions each day. I had not realised its importance till recently. There may be objections to saying the End is happiness tout court, but I agree, I think, with all you really mean.

Yours
C. S. Lewis

--The Collected Letters of C. S. Lewis, Volume 2 (Cambridge: Cambrudge University Press, ), 327