1) It is commonly argued that without a deity, there can be no firm basis for moral law. But what does a deity add? Either we should do what is moral because God is super-awesome, or because he will torture us if we don't, or because our lives just naturally go better insofar as we follow God's law.
But in what world does admiration of someone or fear of their threats yield morally desirable behavior? And if following God's law naturally makes everything go better for us--why not just be moral for THAT reason? Why bother adding a God-concept?
2) The universe is nearly 14 billion years old. It is made up of over 100 billion galaxies, each of which has over 100 billion stars. If God is the Creator of all this, or the "ground of being" of all this, in what sense can He meaningfully be said to be human-like? You can't have a personal relationship with Being. But if God is human-like, in what sense could he possibly be the Creator of such an unimaginably vast universe?
3) The ancient Greeks, the ancient Mesopotamians, the ancient Egyptians, as well as modern Jews, Muslims, and Christians all have deities. Let's assume for the sake of argument that at least one being exists which is worth calling a deity. On what basis can we argue that THIS mythological system's deity is more likely to exist than THAT one's? And what differentiates Christianity from any of these other mythological systems? They all have resurrections, miracles, and virgin births, after all.
4) Theists like to claim that the universe could not possibly have just popped up out of nowhere--it MUST have had a cause. But before the universe, there could have been no space or time, and without space and time, there can be no causality. Why apply an inside-the-universe concept to outside-the universe?
Besides, however unlikely it may seem that the UNIVERSE has always existed, or that the UNIVERSE just popped into existence out of nowhere, how much less likely is it that a DEITY has always existed, or just popped into existence out of nowhere? After all, a deity must, by definition, be larger and more complicated than a universe.
These arguments (none of them original, probably) show why I see Christian apologetics as a doomed and silly enterprise. Am I missing something here?