Atheism is the DEFAULT position. The burden of proof is on the Christian asserting God exists. All we're asking is to see the convincing empirical EVIDENCE.

You are right that the burden is real, and a Christian who asserts God exists owes reasons rather than assertions. But “default” is doing more work in that sentence than it can bear, and the demand for empirical evidence quietly settles the question before it is asked.

1. The burden does fall on the one who claims. Anyone who says 'God exists' is making a claim about reality and should support it. That is fair, and the Christian who answers with 'you just want to sin' has changed the subject rather than met the burden. The arguments exist; they should be given.

2. But 'there is no God' is also a claim. Gregory Koukl's point is that everyone who asserts something about reality owes support for it, including the assertion that reality contains no God. 'I lack belief' and 'God does not exist' are different statements, and the slide between them happens on both sides. If you are only reporting a lack of belief, no argument is owed and none is possible; if you are asserting a fact, the burden is symmetrical.

3. There is no neutral starting point. Everyone reasons from assumptions they did not prove first: that the world is orderly, that the future resembles the past, that our minds can reach truth. The question is not who begins without presuppositions, since nobody does, but whose presuppositions can account for the things we all rely on.

4. The empirical demand assumes empiricism. 'Show me empirical evidence' is itself a philosophical thesis, namely that only what can be measured counts as evidence, and that thesis cannot be measured. It is not a neutral request for data; it is a rule that excludes a category of answer in advance. Rules like that need defending too.

5. Much of what you know is not empirical. The laws of logic, the reliability of memory, the existence of other minds, and the difference between right and wrong are not testable in a laboratory, and no one seriously doubts them. If the standard is 'lab-detectable or false,' most of what you believe fails it, including the belief that your reasoning is reliable.

6. Weighing a non-physical God is a category mistake. Requesting a physical measurement of a non-physical being is like asking how much the number nine weighs. The appropriate evidence for a non-physical mind is philosophical and historical: contingency, fine-tuning, moral obligation, and above all a resurrection claim with early, named testimony (1 Corinthians 15:3-8). Hebrews calls faith “the assurance of things hoped for, the conviction of things not seen” (Hebrews 11:1), which is confidence resting on evidence, not a substitute for it.

7. There is positive evidence, and it is public. The universe began to exist; its constants sit in a life-permitting range; objective moral duties point beyond human preference; and the resurrection is a historical claim that can be investigated with ordinary historical tools. None of these is a mathematical proof, and together they are a cumulative case rather than a slogan. Scripture makes the same claim: “The heavens declare the glory of God” (Psalm 19:1), and what can be known of God is plain because he has shown it (Romans 1:19-20).

8. The 'default' label privileges one side. A newborn is not a philosophical atheist; the label describes a considered position, and considered positions need reasons. Meanwhile the great majority of humans who have ever lived have believed in some divine reality, so if prevalence settled defaults, the default would not be atheism. The word is doing rhetoric's work, not philosophy's.

9. The method excludes the conclusion by construction. If the rule is that only repeatable, measurable events count, then a God who acts in history can never be detected, and the verdict is guaranteed before the evidence is examined. That is not a finding; it is a stipulation. It also cannot explain why the universe exists, why it is intelligible, or why reason itself is trustworthy.

10. Everyone trusts what cannot be proved. You trust that your reasoning is reliable, that your senses report a real world, and that truth is worth pursuing, and none of those commitments is empirically verified. The Christian says they are borrowed from a God who made a rational world and rational creatures. That is an argument to be weighed, not a maneuver. Paul told the Areopagus that God has given assurance to all by raising a man from the dead (Acts 17:31), which is a public claim rather than a private feeling.

So the burden is fair, and the evidence should be given. But the request is not neutral: it specifies in advance what kind of answer will count, and then treats the absence of that kind as the absence of evidence. The real question is which worldview can account for reason, morality, order, and the reliability of the senses.

Sources: William Lane Craig, Reasonable Faith; Gregory Koukl, Tactics; Alvin Plantinga; J.P. Moreland, Scaling the Secular City.

Related challenges:
• IF God exists, He’s maniacal. If He WANTED to forgive sin, He’s 'all-powerful' and 'all-loving' – He could just, SHAZAM, forgive sin. Instead, He sends down His only Son to be slaughtered and murdered to take care of the sin problem. Now THAT’S evil!
• I hear a lot about “intelligent design.” Has this now proven God and falsified evolution?
• How would you respond to Victor Stenger’s stinging assertion that religious argument leads universally to dismal failure and untold suffering?