If you want to go down the road of solipsism and epistimological nihilism (which is essentially to detonate the nuclear option of debate), and declare that believing that we exist is the same kind of belief as belief in invisible deities, then you are free to do so. But it is not a particularly pragmatic approach. Essentially to take it to ad absurdum the fact that I believe I exist means it is also perfectly rational to accept that there is a purple toad that lives in the center of the earth and controls world events (including weather). Both are faith based positions right? If you are willing to declare that the Yahweh is on the same grounds as my purple toad, and the probability of either is equal then sure.