The existence of God does not necessitate that any religion is true. God or gods if real, could be many different things. We would be considered gods by humans a thousand years ago.
For a religion to be true, it would need to be formed under the direction and authority of a god. It is entirely possible that religions may be form without any divine contact at all, and even when there is any(Divine contact) , the resulting social structure may have nothing to do with the initial contact, unless communication is maintained.
#THEREISROOMFORCONSTRUCTIVEARGUMENT .