One of the great things about stained glass in older churches is that it often preserves an expression of orthodox faith even when the people who now use the building are, well, no longer so orthodox.
This beautiful example, from a church I won't name, carries the motto "Thou art the Christ, the Son of God."
The Episcopalian congregation of this church is, I gather, one of the more "progressive" in California. Which is saying quite a lot. But no matter what moral and theological errors may be preached from the pulpit for a few passing years, this window will still be there, silently insisting through its beauty on the most important Truth of all.
I like that thought.