Mate. Thanks to going to all that trouble, but really it wasn't necessary, no really it wasn't. :)
What is your reply?
My reply would be that I once had to go see the school priest. He asked me what I would like to confess. I'd not actually done anything wrong (I was only 8 years old) but i'd been put under strict instructions from my teacher to think of at least three things that I needed to be absolved of. Well, tricky. But bless my little cotton socks, I tried.
I was, looking back, mightily impressed by the poker face the priest kept as I told him solemnly that i'd sinned and I hadn't actually changed my socks when I told my mum I had.
I got three hail marys and one our father (Got off lightly there!) and that was that. I was free from my evil doing. (phew)
But what is my point?
I think that by that point, even the priest knew how daft it all was. But we all went through the motions because we all believed that we had to, even though no one can prove to us that we do.
But isn't that the point? :)
Bertrand Russell said that there is a teapot orbiting the earth. Does that mean I should be out in my garden night upon night, telescope trained to the heavens trying to catch a glimpse of Haley's Wedgewood?
Of course not!
It's not up to me to prove that there isn't a large tea cup who's spout we only see once every 365 days. No, it's up to him to prove to the rest of us that there is. Same with this. The one that is so convinced about there being a creator and a divine trinity and all that should have the onus firmly placed on his shoulders, to back it up and show you they're right.
Can you prove that religion was only created by people to control masses and not that it became a weapon of manipulation somewhere in the process?
I don't need to. To quote Christopher Hitchens. "What can be asserted without evidence, can also be dismissed without evidence."