Theists, I suppose, are persons who believe in “God's” existence. Atheists are persons who deny the same.

Such statements may be suitable, and even adequate, for many proper purposes. In several contexts it is silly or malicious to interrogate them closely. Even in theology, which is, or should be, some kind of science, they may have, and they do have, their use and their propriety. For many theological purposes, however (and also for some others) they are far too vague. It may be wrong, no doubt, to tell a theologian that he must either produce an accurate definition of what he means by “God” or be forever shamed.