How to rid myself of lasting Christian beliefs?

I was raised Christian and held Christian beliefs for my whole life until around age 13 where I lost my faith. Lots of things are still ingrained into my brain that I'm not sure how to get rid of, but I'm not even sure if I should get rid of them. I don't believe in God or the Devil or Heaven and Hell but I think I do believe that we (and every living creature) has a spirit or soul, whatever it's called. On another subreddit when I mentioned something about being agnostic and said something about spirits, somebody replied saying that my belief in spirits was Christian and that it was something I need to get rid of which I had never even thought it was a Christian belief before. The reason I think we have souls is because I don't really feel much of a connection with my body, I feel apart from it and the only explanation would be that we do have souls seperate from our bodies. I think that the soul may die when the body does but that they are seperate. I also am unsure about the fact that I keep saying and thinking "that's how we were made" when talking about how humans are. I don't believe that a Creator made us but that the simple existence of things made us able to have existence, if that makes any sense. How should I go about this?