No offence, but that seems like the wrong order. Indoctrinate him till 18, then let him make up his mind about what he wants. IMO, he should be left alone as far as religious thought until 18, then given the choice.
I agree, but in the real world, that is not what happens.
Here in Australia, my daughters were made to go to 'Religious Instruction' at primary school.
So when they informed me, I said "That's nice, let me know when you get to study the Muslim Religion".
...blank looks and they asked "What !!"
I repeated what they said "Religious Instruction" - then added "there are many different Religions".
...oh, we are only doing Christianity" they replied.
So I simply said "Does that sound right ?"
They thought about it and said "No".
They decided to attend, but with an open and critical mind.
After a few sessions, they reported that "this Christianity stuff is full of contradictions, and seems to be just like 'fairy stories' - as there are no facts to back up their claims".
I agreed and suggested they also look at other religions.
fyi. They found that most of the other Religions also had similar 'fairy stories' along with 'no facts' to back up their claims, so I said "Welcome to the real world. Each of YOU need to make up your own minds based upon the evidence given to you"...."But Dad, they offer no evidence, just a lot of singing and comforting words".
"Yes, they do, don't they" was my reply.