Salutes to Angels

“Incense and Hail Marys are in quite different categories. The one is merely a question of ritual: some find it helpful and others don’t, and each must put up with its absence or presence in the church they are attending with cheerful and charitably humility. But Hail Marys raise a doctrinal question: whether it is lawful to address devotions to any creature, however holy. My own view would be that a salute to any saint (or angel) cannot in itself be wrong any more than taking off one’s hat to a friend: but that there is always some danger lest such practices start one on the road to a state (sometimes found in R.C.’s) where the Blessed Virgin Mary is treated really as a deity and even becomes the centre of the religion. I therefore think that such salutes are better avoided.”
-C. S. Lewis, The Collected Letters of C. S. Lewis Volume 3, page 209