I am obviously in the minority here but I think that's a call that is correct. It fits the "drawing attention to ones self" part of the excessive celebration rule. You want to get on a knee and point to the heavens, do it in the team box.
Let the blasting begin....
He just scored a touchdown, attention is already on him. by kneeling, and then pointing skyward, he is prolonging that attention on himself. (The fact that he is doing so in a religious manner, to me, doesn't change that).
I think He would understand if you waited the 30 seconds or so it took to get off the field to kneel and thank Him.
Religion is always a tricky subject, but by allowing one type of religious act, we open the door for any number of cases- "In my religion, we praise Him by lying on the ground making snow angels".
That being said, it did not seem like that big a deal. But there is very little context on which to judge it. Had this type of act been discussed previously? Were there other factors involved, such as previous celebrations, the emotions of the game, etc.?
In that official's judgment at that time, in the context of that game, the act rose to the level of a foul. Others may not agree. With the evidence I have, it's hard to fault the official for making the call- or frankly not making the call if it he had not.
I probably would not have flagged it the first time it occurred, but would have made it known that it should not happen again to prevent an escalation of who can be the most pious.