A moron's reply:
The shortest answer is "they don't" and the question is sort of like asking "why do you beat your wife?" You are implying guilt without justification.
But assuming the best interpretation I will rephrase it "Why do Christians (and Muslims) teach their children to believe in their religion they're old enough to think for themselves?"
The short answer here is that we do this, largely, because like everyone else we love our children and want to teach them the truth about the world as soon as possible so that they will be equipped to face the world as it actually is. Compare teaching faith to teaching a child to brush their teeth. One could let a child wait until they are old enough to decide for themselves if they want to brush their teeth but if you did this the effects of the decision would be long lasting. So a loving parent teaches their children the truth about God and teaches their children to brush their teeth. It is well known by parents then when given their own power to decide some will turn away from God and some will stop brushing their teeth... but that sort of thing is out of the control of parents and so they simply do the best they can with the time they have.
Thanks for your reply. I usually get ignored. So this is progress.
I wouldn't compare teaching a child about your religion to teaching them how to stay healthy.
In my opinion the real reason for the religious brainwashing before the victims are old enough to think for themselves, is if you let them grow up first, they will never believe the Christian nonsense for example the totally ridiculous (not to mention impossible) resurrection of a decomposing corpse.
Also, I have seen this explained by a Christian who admitted it was very important to not let their victims grow up before trying to indoctrinate them.
You are not just Christian. You're Evangelical. This means you have probably thrown out human evolution. Your victims learn nothing about how the world works.
Fine with me. It's not my problem. I just hope you realize your children might think you're insane after they go to a university, which can be avoided by forcing them to go to a worthless Christian college.
There is no hope for this country. The brainwashing will never end. The brainwashed will grow up to be brainwashers.