If there is one god and thousands (millions?) of fake gods, how do we know that your god is the real god?  The real god might even be female!

If a god exists then it seems that trying to fit religious ideas of one of the many supposed gods would be a poor strategy.  A better strategy would be to be nice to other people, protect the weak, feed the hungry, etc.  Almost all religions favor such things.

Any religious effort spent on supporting or learning about one particular religion would reduce the religious effort spent doing good deeds and therefore be most likely to reduce the probability of being rewarded in whatever version of heaven might exist.

As for following moral codes, the vast majority of atheists agree on a moral code that prohibits genocide and rape.  I wish the same could be said about clergy.