Edmund, all I can say is that I have questioned my family's belief, and my own, and yet still come to the point of faith. I've thought very carefully about whether I am allowing myself to be deluded, brainwashed or similar, and reading books like The God Delusion haven't convinced me otherwise, or in fact those of more learned theology scholars. You're right to say there isn't quantifiable proof we can point at and say 'ah, that proves it beyond doubt,' but there isn't quantifiable doubt either. Saying that I am not a fan of the god-of-the-gaps argument and prefer to wonder at what I believe to be God's design through looking at science and being amazed at discoveries we make.
I'm really glad you're content with the world around you, contentment is hard to find and it's great when people can come to that place. I don't think I am leaning on a man-made god in order to feel better about things; my faith doesn't promise that suddenly everything will be made better for me and I'll feel happy. Far from it. It's more of an understanding of the whole story, a glimpse of the power and the beauty behind it all, and the justice which we all yearn for in every human story I believe will happen. I cannot be content with the world the way it is because it is shit, screwed up, although glimmers of hope and goodness encourage and inspire me everyday.
I hope I am honest enough with myself not to be dragged into delusion. I'm really very rational, I see through fallacies quickly and don't allow myself to be drawn into mythical and farcical tales, because I value my reason. However, my experience of God is grounded in reality for me, experience of transformation and hope and peace which belies understanding.
I'm more than aware this is not enough - it's one random on the internet saying 'I feel God's presence' - but it's what I can offer. It's my life's experience, through darkness and light, doubt and fear, always returning to the truth I hold dear.
Saying that, I don't think school is ever a place for people to tell others what to believe, particularly children. They should be taught about religions, not told one as true, for they need to make up their own minds. They'd be better teaching use of critical faculties, and told that these are all things people believe, and they can explore them for themselves if they want to, or not.