Why don't you believe in one specific religion?
Because I do not/cannot believe in an "absolute truth".
All religions are human-made. At some point somebody claimed to have an encounter with the Divine and that person or persons convinced a bunch of people to be their followers/disciples. From then on it's just a massive game of "telephone" as the message gets passed down the line it gets contorted and adjusted and interpreted in different ways.
Groups get big and leaders arise and those leaders have conflicting interpretations of the message or of what happened and the big groups ends up splitting into smaller groups. Those smaller groups get bigger and divide into smaller groups again.
Religions are simply cellular biology in macro proportions and none of them actually care about "truth", they just want to be "right" so they can say they have life "figured out". Break life down to a formula so it's not confusing and terrifying anymore.
Because if you have life "figured out", the onus isn’t on you any longer to change. You don’t have to think, you just have to follow the formula.
And that's not "truth" and it's definitely not "absolute" either.