No they aren't. No one said not to practice and the gov't is the one prohibited from the establishment of a preferred religion. Christians have a rightful concern of the worship of other gods. It is prohibited by the Triune God and 'strange gods' fared poorly in the OT. If the belief in "G"od isn't the biblical one, it is from Satan. 'Joint' prayer is synergism and should be avoided.
Agree completely