As an agnostic, I would say that I do not know if any particular religion or all religions are false or not, although I would say they cannot all be true, since they contradict each other in certain important details (for example, views about Jesus by Jews, Christians, and Muslims). I would say that "faith" is unreasonable. I also think this demand for faith is insidious and often corrupting.
But I would say that claims of proof for the existence of God are false. The Catholic church has--or had--as one of its doctrines the idea that the existence of God could be proved by "unaided" Reason. If that were the case there would be no need for faith, but the Catholic church has never worried too much about being consistent.
One would think that if one wished to have a religous viewpoint, that at least you would want to limit the assumptions to as few as possible. The Catholic church seems to embrace the opposite view--the more unprovable assumptions the better. They don't call them assumptions though. They call them "mysteries" (for example, the Immaculate Conception). I suppose you could call yourself a Catholic and not believe in the Immaculate Conception but it is an official doctrine.