Indoctrination was the term used by the church I grew up in to describe their youth teaching and is quite an accurate description of the process.

I've got comments elsewhere in the thread on why I don't think indoctrination is a great term -- might want to check those out and continue that conversation there.

The thought about this seems to be along the lines of it is easier to convince someone being introduced to arguments for/against religion for the first time than someone that has heard it all before and come to a conclusion. Even easier if you only introduce one side to this person.

Interesting. If it helps, I thought of myself as a believer in the Greek Gods in elementary school, fiercely resisting the evangelism of my classmates... at any rate, I was definitely exposed to religious teachings at various parts of my life prior to my conversion, but nothing really ever stuck -- and my parents are both pretty firmly in the non-religious camp. So I'd say growing up, I definitely had a decent background on core arguments from both sides of the fence.

To a third party hearing about your experience it sounds like you were particularly convinced by the group this time. However, you've provided nothing that would say groupthink was not the cause, just that it was super effective this time. One of the things that is striking about studies of groupthink is how rarely people realize that they were influenced by it.

Thanks for noting that -- I'd have a hard time pinning it on groupthink. The room wasn't full of people being "moved by the spirit." Some people were singing, some were praying by themselves, quite a few people were just using the space and time as a place to hang out and chat and chill -- it was a pretty diverse group, and not everything or everyone was moving in the same direction or doing the same thing. In fact, when this particular experience hit, I distinctly remember being by myself -- not looking at or thinking about what the others were doing, but really wrapped up in my own experience.