Atheists like to think theists alone bear the burden of proof when it comes to the question of God’s existence. They assume atheism is the default position unless, and until sufficient evidence for God’s existence can be mustered. This is simply not true. Atheism is a worldview (or, more accurately, is a component of many worldviews), just like Christianity, Buddhism, and Hinduism. All worldviews make truth-claims, and he who makes a truth-claim assumes the burden of proof to demonstrate the veracity of those claims, including atheists. Each worldview must stand on its own merits. The lack of evidence for other worldviews is not in itself evidence in favor of another. That’s why it is illegitimate to think a (supposed) lack of evidence for theism is itself evidence for atheism.
All worldviews are charged with explaining reality, both as it is, and as we experience it. Atheism is no exception. If anyone is to take their worldview seriously, atheists must explain the existence of the universe, free will, rationality, consciousness, and the like without reference to God. Indeed, they must show that an atheist explanation is superior, and more likely than other theistic alternatives. This project is doomed to failure. The explanatory scope and explanatory plausibility of atheism is inferior to theistic worldviews. How so?
Atheism requires that we believe the universe just popped into existence out of nowhere, caused by nothing. Theism, on the other hand, posits an eternal, intelligent agent who caused the universe to come into being. Unlike atheism, this is in line with our modal intuition that being only comes from being, not non-being.
Atheism requires that we believe free will is an illusion, because as mere physical stuff, humans are not exempt from the determinism inherent to purely physical systems. Theism, on the other hand, posits the existence of an immaterial entity within man, allowing him to transcend physical determinism, to freely choose among options undetermined by external physical constraints. Unlike atheism, this is in line with our experience of genuinely choosing A rather than B.
Atheism requires that we believe rationality developed by evolutionary means, and it is by pure accident that rationality helps us to discover truth about the world. Theism, on the other hand, posits that God is a rational being. Humans are rational because we are made in God’s image, and God desired to endow us with the means to discover true propositions about our world.
Atheism requires that we believe consciousness arise from non-conscious matter. Theism, on the other hand, posits that human consciousness arises from spiritual, rather than material substances. Consciousness is a function of the soul, and is derivative of the consciousness exemplified by a personal God.
Which worldview better explains the world and our experience of it? I think the answer is simple. Theism has greater explanatory scope and explanatory power than atheism, making theism the preferred worldview. Theism does not need to deny something so intuitive as the principle that being only comes from being, that every effect requires a prior cause, or that humans have causal powers undetermined by other material processes.
For further reading see my article titled Not so Fast: There is no Presumption of Atheism.