I'm a former fundamentalist Christian who deconverted because of issues that relate specifically to Christianity: an eternal Hell, lack of evidence for the resurrection, the trinity not making sense, rigidness and conspiracies, and so on. I believe in one God, who is completely perfect in every way and is imminent both out and inside of creation. I believe that everyone will be saved and that the religious life fundamentally comes from purifying the heart. What is a religion that may fit my beliefs?
Hard to say because this is very limited information to go on.
I would guess some form of monotheism, likely Abrahamic. Not sure if there's an existing religion within the Abrahamic paradigm that would meet all of your beliefs, though. I'll defer to some of the non-messianic Abrahamics here.