A few years ago I ran across a statement by Jean-Paul Sartre which seemed to imply that if there is a God, then there can be no human freedom. That thesis struck me as questionable, but at the time I did not pause to examine it. More recently I ran across a similar, more explicit statement by Kurt Baier, and I decided the time to pause had come. My knee-jerk response to Baier – and I confess it was probably nothing more – was, ‘Why can't there be human freedom if there is a God? Indeed, can there be human freedom if there isn't a God ?’ The second of these questions has proved to be the more provocative to me, for the more I have thought about it, the more it has seemed to me that it is the atheist and not the theist who should be on the defensive about libertarianism, i.e. the position that human beings do act, that human actions are not determined, that we are the sole cause of our actions, and that all things remaining the same, we could have done otherwise. Indeed, the more I thought about that question – Can there be human freedom if there is no God? – the more convinced I became (and still am) that the atheist has no good reason for believing in libertarianism. Note: I am not saying that atheism is logically incompatible with libertarianism. Perhaps it is, but if it is, that is not yet obvious to me. Rather, I am saying that an atheist who believes in libertarianism must believe in it on the basis of faith and must hold this faith in opposition to the only type of evidence that is available to him. Hence, by denying the existence of God, Baier and Sartre do not make room for human freedom; they make belief in human freedom irrational. By contrast, I shall argue, the theist does have a good reason for believing that humans are free. Let's take separate looks at Baier and Sartre; then I shall summarize the substance of my position.