The type of person you're describing would be more accurately described as a devoutly religious theist. Such adjectives exist for a reason. They allow us to be more specific. Theism by itself is a broad term. As noted by Wikipedia, it derives from the greek word theos, which means "god", and we all know what an "ism" entails. Further, I didn't say that you are a theist. I said you are inclined towards theism. That is, you are inclined towards what is essentially "godism" (a few people actually use that word). If the devoutly religious theists want to try to hijack the word, and play games with it for the purposes of excluding certain people from their 'group', then good luck to them. Perhaps over time the definition proper will change. But that hasn't happened yet.