That's right, Peter. There isn't. Actually, there can't be, because spiritual things are, by definition, things that are happening "in spirit", not here in this dimension of existence. ;-) That is, they are presumed to be happening outside the parameters of this physical reality in which we seek and find empirical evidence. Although spiritual events may be observable in some way by various individuals, there is probably no way of assembling any empirical evidence, as it would be considered simply anecdotal evidence..."hearsay".

There have been some interesting instances of apparent ghostly phenomena that have shown up in photographs or on security cameras. I've seen some of that. That is evidence of something all right, but it's hard to say of exactly what... At any rate, it's not evidence of "God". At least I wouldn't think so. ;-)

There might well be ghosts, after all...and still be no God.