"I struggle knowing when to sacrifice my own interests in art for the greater good of Christendom."
To which I reply, "Me, too.". The greater good of my family, my friends, my health, my finances...
Minds (shockingly) greater than mine have considered the question. I can't heartily or often enough recommend J.R.R. Tolkien's short story Leaf by Niggle to those artists who find themselves pondering thus. It is a meditation on the life of an artist (the title character, Niggle) and explores his responsibilities to his neighbors (the "greater good"), as well as their responsibility to him and his responsibility to his own art, as well as... well, it just explores a lot for a short story. And it's Tolkien.
I have found the complete text online before, but have lost track of the link. I'm also not certain about copyright questions, so I will leave the clever reader to find it on his/her own.