But how? To brainwash you have to make someone believe something that isn't true. Now take someone from a philosophical or scientific culture and they are used to questioning assumptions, disbelieving things at face value, a culture of pursuit of truth. But now take someone from the church. Do you know what they say in church? They say you are good if you believe. What's more, the more you doubt the gospel, and still believe, the better you are. In other words, the more stubborn, the more unwilling to listen to counter arguments, the more blinded by your one faith, the better person you are. In the church. Now take someone like that and feed him a bunch of malicious bullshit. Is it ANY wonder he's gonna believe it?
That's the whole problem with religion. The sheep mentality. No, don't look there, look here at the pretty gospel. Don't listen to people who deny it, they are trying to deceive you, listen to us, only we tell the truth. It's dishonest, it's harmful and it's a fantastic way to manipulate people.
That's really my objection to religion in general, chiefly Christianity which I know. Everything else is secondary.