If you believe that there is a single Higher Power, or some single Divine Source, then yes, I would say all religions are reaching out toward that source and trying to relate to it. They just have different ideas about the nature of the Divine.
go on UTube and watch "ZeitGeist" - I think you can see it all on that tiny screen - or you can get the DVD somewhere. It's full of the most interesting stuff I can imagine - from the old gods of ancient times, to the attack on the Trade Center in 2001 and on into the money matters of the United...