Yes, I agree with you in principle.
No doubt that most of the folks that settled this country were of Christian decent and that is a big part of our culture. We are just lucky that we had men such as Jefferson, Adams and Washington who were intelligent enough to see through much of the religious folly that had fallen on most common men. That they had the insight to realize that an organized state sponsored religion would be a dual edged sword, so to speak and that a state religion would lead to tyranny. Just look at countries like Iran.
BTW, I was raised in a very strict Christian household where both Santa Claus and the Easter Bunny were banned! When my daughter was a teen, she asked me why we didn’t belong to any particular church. I told her that I felt that it would hinder her from discovering for herself what the world and religion were about. That if it truly were going to mean anything to her that she would have to work that out in her own mind.