Moderns insist on proof; scientific proof, economic proof, psychological proof, theological proof. Proofs are collections of anecdotes, incidental occurences repeating themselves over and again until observers are reasonably certain the anecdotal occurrences will manifest themselves often enough to be reliable.
The most reliable of proofs is anecdotal and so not absolute. Even the most accurate of measurements represent truth rather than constitute it.
So, moderns can hope for verifiability, accurate measurement along with trustworthy transmission, unbiased, dogmatic only in the purer sense. Moderns are disappointed regularly, then, and finally conclude that truth is actually no more than information filtered through one's own need and ability to assimilate information (Kant). So, the genius has truth the researcher can only guess at and the researcher has truth the unseeing cannot find.
So, it is Christmas and we are back to Nietzche. Christmas is complicated.
Unless, that is, there is a reliable means to know that God is and that the God who is cares about people who are. The proof is accomodational but valuable, if we define value as that which we would trade things we know to be of worth for this proof.
We are unable to find valuable proof without faith. Faith is the natural or expected end of intuition. One can base his faith/intuition on other means of knowing; senses, memory, authority or experience but the final leap across the abyss is one of intuition.
Why not for us, a leap, since God, in Christmas, takes such a giant jump? If God knows anything, let alone all things, God must know that He is about to pay a huge price for what He could command. This is a leap of faith, not blind, but nearsighted in its hopefulness. If God will leave Heaven with hope in faith for us, why should we expect to enter Heaven without hope in faith in Him?
Somewhere, today, Oh, God,
Let me leap into what I think is danger,
displacing my comfort
for what I think is sacrifice,
so that I might find myself,
nestled securely in your arms,
when I land.