Where's the evidence?

If, as many christians repeatedly claim, there are heaps of evidence that their god is real and that their religion is the only correct one, why can't they ever present any of it? All they ever do it tell others to look for it themselves.

It would be just as valid to say there are heaps of evidence that The Flying Spaghetti Monster is real. Anyone who doubts that should look for the evidence themselves and they'll find it's true.