And, likewise, just because the catholic church says a just morality can only arise from the bible, doesn't necessarily make that true, either.
The Bible itself agrees with you. Morality also arises from our conscience. Hindus won't be condemned because of what the Bible says. Hindus will be condemned because they did things they knew were wrong.
Those that never did anything against their conscience will not be condemned. Unfortunately, God who knows the future, has already weighed in, that none of us achieve that.