Strange (to me) flag flying near a Stars and Stripes?

[RED]

Solid white except a Blue Union Jack bearing a red Christian Cross. I cannot recall ever seeing one like it.

[Phloating Phlasher]

Can you post an image?
it sounds vaguely like a "White Ensign" as you describe it.
https://en.wikipedia.org/wiki/White_Ensign

[RED]

No photo but I found what it is...

"The Christian flag is a white flag with a red cross in the center of a blue canton, and is used by many Christian denominations. The white field represents purity, peace, and holiness, while the blue canton represents truth and loyalty, and possibly baptism or heaven. The red cross is a symbol of Christ's shed blood, and together the symbols represent the basics of the Christian faith."

[bruce]

Re: OP. Christian flag. Very commonly used in churches across America. Typically displayed on one side of the platform or room across from the US flag. Sincerely. bruce.