The famed atheist Richard Dawkins has often said (as here) that he does not consider it any different to not believe in the Christian God than to not believe in Zeus or Thor or Mithras or any other non-Christian deity. "Everyone's in atheist concerning some gods; we've just got one god further," he says. Now, being the Anglophile I am, I'm always so tempted to treat seriously any words spoken in a refined English accent--I just love the way Dawkins says "Zyoos" for Zeus--but in this case I'm afraid that even his silky Oxonian tones can't salvage Dawkins' rather silly statement.
The problem here is one of equivocation; that is, the same word, "god," is being applied to Zeus and Thor and Mithras and YHWH, but what being a "god" means in each case is radically different.
In the mainstream orthodox Christian tradition, when we speak of "God" (even prescinding from the whole question of Christ and the Trinity and any personal attributes), we mean the very ground of existence, the first cause of all things who is Himself uncaused, the source of all goodness and love, that than which nothing greater can be conceived, eternal, omniscient, omnibenevolent, omnipotent. We are making claims that matter to our entire worldview, that reach down to the deepest metaphysical questions. One can conclude the existence of such a God purely through reason, as in Aquinas' Five Ways, as Socrates did when he said there was only one god, as many a former atheist who has thought about it a bit has done.
When we speak of Zeus or Thor or Mithras or any other "god" of this sort, we are not dealing with anything quite so philosophically serious. None of these are eternal, having existed always. None is the uncaused first cause of all things--each of this has his own birth, and none can be said to have created all. None are all-knowing, all-powerful, all-good: they may know a lot, and be able to do a lot, and do some good things, but they are occasionally ignorant, and often limited, and quite frequently immoral. One could conceive of a universe without the god of the sky or of thunder or of justice, or of this particular god of those things; someone else in the pantheon could take up the role. One would never and could never reason to the existence of Zeus or Thor or Mithras.
These pagan "gods" are high-octane versions of humans, like people with the volume turned up. The Christian God is something fundamentally different. It's comparing apples and oranges... not even apples and oranges. More like apples and wrenches. I don't believe in Zeus or Thor or Mithras because it's unreasonable to, and because they have never revealed themselves, and do not continue to reveal themselves throughout history--I've never heard of anyone in the last 3,000 years being healed of a deadly disease thanks to their supplications to Apollo. But to believe in the Triune God as described above is eminently reasonable, and that reason is supported and confirmed by revelation, by miracles, by personal experience, by faith. These other three poseurs cannot compare. Nice try, Dick Dawkins.