LAMED. For ever, O LORD, thy word is settled in heaven. (Psalm 119:89 KJV)
The late John Warwick Montgomery was a Lutheran and a historian. His apologetics method was to try to establish the "probability" of the truth of the Bible and the resurrection. However, probabilities are by their very nature uncertain. Probabilities do not yield truth or certainty. The propositional truth of Scripture is not a matter of empirical evidences, historical probabilities or rational arguments for the truth of the Bible. According to Dr. Gordon H. Clark evidentialism, historiography, and rationalism all lead to skepticism, not faith. And in fact, since all epistemology begins with unproven axioms, why would the historian fault the Christian for starting with the unproven axiom of Scripture. The Christian worldview is deduced logically from Scripture and we know the historical accounts in the Bible are true because the Bible is inspired of God.
Although I disagree with Montgomery's evidentialism and historicism as the beginning axiom for his Christian apologetic, he is certainly correct that the agnostic is wrong for presupposing the starting axiom of indecision. The atheist is equally wrong for presupposing that the relativism of science and empiricism establishes the worldview of atheism. Both agnosticism and atheism begin with unproven axioms as well.
We know Jesus lived because the Bible says so. There are little to no external evidences for the existence of Jesus.
You can read the quote from Montgomery here:
"Today, especially in university circles, agnosticism has become immensely fashionable. The days of the hidebound atheist appear to be past, but his agnostic replacement is in many ways even farther from the intellectual mainline. The atheist at least has recognized the necessity of taking a position on ultimate matters. The agnostic, however, frequently makes a demi-god out of indecision. Actually— as Heidegger, Sartre and other contemporary existentialists stress— all life is decision, and no man can sit on the fence. To do so is really to make a decision— a decision against decision. Historians, and indeed all of us, must make decisions constantly, and the only adequate guide is probability— since absolute certainty lies only in the realms of pure logic and mathematics, where, by definition, one encounters no matters of fact at all. I have tried to show that the weight of historical probability lies on the side of the validity of Jesus’ claim to be God incarnate, the Savior of man, and the coming Judge of the world. If probability does in fact support these claims— and can we really deny it, having studied the evidence?— then we must act in behalf of them. When Jesus said that he would spew the lukewarm out of his mouth (Revelation 3: 16), he was saying that action on his claims is mandatory. “He who is not with me is against me,” he plainly taught."
Montgomery, John Warwick. History, Law and Christianity: A Vigorous, Convincing Presentation of the Evidence for a Historical Jesus (Kindle Locations 800-809). New Reformation Press. Kindle Edition.