Let them believe their beliefs and you believe yours, God expresses himself in various ways and every one is true.If you dont believe them just stay away.If they are true you are committing an offence if they are false then by staying away you are doing no harm.God is everywhere and omnipresent, If we can worship him in an Idol, why not in a human form, that is the Guru? Dont we worship him in our Parents and the Sun and Fire? Dosent the Gita say him to be present everywhere and worshiping him in the Guru is approved by the shastras.