i'm going to quote from wikipedia for simplicity. please forgive this:
Theism, in the broadest sense, is the belief that at least one deity exists. In a more specific sense, theism refers to a doctrine concerning the nature of a monotheistic God and God's relationship to the universe. Theism, in this specific sense, conceives of God as personal, present and active in the governance and organization of the world and the universe. The use of the word theism as indicating a particular doctrine of monotheism arose in the wake of the scientific revolution of the seventeenth century to contrast with the then emerging deism that contended that God, though transcendent and supreme, did not intervene in the natural world and could be known rationally but not via revelation.
i'm using theism to mean the specific sense, not the broadest one. taking a page from sam harris, i'm talking about theism the way it is practiced by the overwhelming majority of people on the planet. if you want to talk about god as consciousness, or as nature or as some new age-y spirituality and being one with the cosmos, that is one thing. but most people are talking about god as an overseer that requires devotion, praise, prayer, that has given his word in scripture, that insists on dogma and that mandates obedience. this is the practical reality of god in the lives of all but a tiny minority of those that consider themselves theists. this is the god that stands in the way of human development.