I would tend to agree with you - although I do think there is a significant number of people "of faith" who have similar beliefs, the greater commonality is less the exact identity of the god/gods of all religions and their similarities, the commonality is that humanity has such a large widespread tendency towards looking for or at a greater authority in their existence.
I'm not nitpicking the language so there's some flab in that statement but I'm specifically choosing "greater authority in their existence" to convey the idea that it may be a designer, a giver of purpose, a creator, a giver of laws and rules, of care and guidance, of justice, a sense of order in the short and the long term and the foeveroutthere term....I'm suggesting too that "greater authority" also covers the ground of faith, the part of trusting in something that may not be rewarded or punished in immediate gratification or punishment.
All ideas and conception of God exist in a known universe of our own perception at the least (or I guess the most) so while I might think there's no way to know how this came to be or who is responsible, I can allow for greater even "ultimate" forces to be at work. Granted that's more deism than faith and probably covers some atheist ground more than the array of "religious" beliefs about it all, it still lives on that side of the fence, to me.
Peace n love homies!