Can I not profess a religion but still believe in God?

I mean I don't like religion, I find that it separates people. Most of my friends are Christians (not because I only choose Christian friends but as most people in my class are Christians) but people keep telling me I need to have a religion. People keep trying to persuade me to think the way that they're thinking. I believe in God, well to be more exact I believe in Karma and I believe in Heaven. The thing is, I'm not planning to ever believe in one religion because I will never be fully committed to it. I will always doubt it. I'm open minded, always try to take into account other peoples' beliefs. I do kind of add it to my own beliefs. But in all the religion I've witnessed so far, there's never been a religion were I really believe it. Also, I'm not trying to insult religion or anything, I respect people who do and find they do it because they think it's the right thing to do. So I mean no offense. I'm just interested in what you have to say. What are your thoughts on this?