Before i begin, I would like to create a distinction between teaching about a religion and forcing your child to practice it. These two are separate, And I will be arguing the teaching side. Teaching religion to your child is not a bad thing by itself, And can have many positive benefits. It could teach your child how to act, How to be a good person, Or reassure them to an extent. Simply teaching a religion is not the same as forcing your child to practice it.
Your kid needs freedom. Your kid should be allowed to learn any religion or just not believe in any of them. If you are religious, Your kid doesn't have to be. Your kid needs to be able to learn on his own what religion he wants to believe in, Not to have it force-fed into his mouth without his consent. SO again: Your kid needs freedom.