[Reprimanding a Christian poster for citing Hindu doctrine in a historical context.]
IMO Christians should not give any crediblity to false religions by citing their beliefs. God wants all of His children to be followers of His Son, Jesus Christ. Hindus, Buddhist, Mormons, Muslims, Jews, and all the other non Christian religions are not followers of His Son. To a Christian those are all false religions, and should not be taken seriously unless they become a threat. It does not matter if a particular religion was around long before Christianity. When Jesus came to earth, all other religions became void.
Any amount of time a Christian spends studying false religions is stealing time away from God. Any amount of time Christians spend time in conversing with others on any false religion has stolen time away from the Christian's great calling of evangelism.