Dear Mr Smith, first I want to thank you for your military service.
As others have said, the 1st Amendment, like much of the rest of the US Constitution, is a restraint on Government actions. In the ‘religion’ clause, a ‘forced’ church is forbidden while no religion may be banned. In the various tests of this clause over the past centuries, interpretations of the ‘free exercise’ have become totally open EXCEPT for violation of civil constraints like human sacrifice and the like.
Individuals, outside government, are not constrained by this ‘religion’ clause, save by being protected by it from government actions. Thus all citizens, regardless of affiliation or lack thereof, have this protection. Nowhere is any flavor of Christianity mentioned here or anywhere in the US Constitution.
Frankly, your post confuses me but I hope I have offered some clarity.
Someone wrote something worth reading!!
T.y.!!