"Idol worship is a sin".....many of us have heard it time and again, though few of us have done an exegesis on it.
In the day & time it was laid down as a commandment.....this was the context. The Israelites were leading very sinful lives by all means, openly fornicating, having orgies, being drunk most of the time AND in these drunken festivities worshiping anything and everything they found. That was considered "idol worship".
Fast forward to today, majority of the Hindus I know do not worship in that context....they are pious when they are worshiping and to my knowledge they are not worshiping the object ....but rather the diety or incarnation the object represents. So this isn't the "idol worship" referred to in the Old testament.
Also most churches over the world (Protestant & Catholic) have such representations of Christ/Mary that people in effect worship. My point being this isn't considered "idol worship".
So bottomline....what Hindus do isn't "idol worship"....atleast not in the way the Old Testament meant it.....for if it does....then by all means a huge number of Christians are also "idol worshippers".....Besides the "10 commandments" in Old testament were in effect replaced by "2 commandments" in the new testament. Hope that helps.