An ant could never understand anything about us, so why would we think we could understand something about God?
I am not sure that the problem is that people throw around words [about God] so carelessly, but that the only words we humans have to use are human words, bound by time, space and human experience. Whatever God is, God is surely beyond the boundaries of human life. So the more specific we are about God, the less accurate we probably are. Let me repeat my favorite analogy. Horses cannot escape the boundaries of what it means to be a horse, nor can a horse view life from any other lens or perspective save that of a horse. Therefore a horse could never describe what it means to be human. In a similar manner, a human being cannot escape the boundaries or perspective of what it means to be human and therefore can never define or describe what it means to be God.
Is it really correct to say that just as a horse cannot describe us, so we cannot describe God? Are the two situations analogous? Francis Schaeffer has a great insight in The God Who Is There that helps to answer this question.
He points out that God is both personal and infinite. When you consider man and the animals in terms of our creatureliness—our limited nature and dependence on God, we are of course closer to horses than we are to God, and there is a great chasm between us:
In this sense, there is no connection between God and man—He is completely "other" when it comes to His infinite, uncreated nature. But in terms of our personhood (the category that matters when we're discussing comprehension and relationship), we are closer to God than we are to animals:
We are made in the image of God, and so we share many things with God, though we are finite. And it's because we share this image that we're able to understand what it means to say God is loving, and just, and merciful, and good. Because we can relate to God as personal being to personal being, "man can know God truly, though he cannot know God exhaustively."
A horse, on the other hand, is forever on the other side of the line in the category that matters.
Schaeffer's story sums up the answer to this objection:
A man from Israel who was an atheist wrote and asked me, "What sense does it make for a man to give his son to the ants, to be killed by ants, in order to save the ants?" I replied that it makes no sense at all for a man to give his son to the ants, to be killed by the ants, in order to save the ants, because man as a personality is totally separated from the ants. Man's only relation to the ants is in the areas of Being and creaturehood. However, in the area of personality man's relationship is upward to God, and therefore the incarnation and death of the Son of God for the sake of man's salvation are sensible.
The reasonableness...of communication between God and man turn[s] on this point—that man, as man, is created in the image of God.