Proof, evidence, affirmation, and confirmation ....some would say that all of these are subjective to the one in search of any one of these. Often, we fail to see the forest for sake of the trees.
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. -Romans 1:18-20
Paul's letter to the church in Rome reminds us "the unrighteous" actually suppress the truth. That begs a couple of questions...
a. What makes one "righteous"?
b. Why would an un-righteous person suppress truth?
The answer to question 'a.' may very well be in the same letter of Paul's. In Rom. 1:17 Paul states... "For in it the righteousness of God is revealed from faith for faith,...". Righteousness belongs only to One ...that is the Creator God. His righteousness is gifted to us through His Son and only by His Good Will. Believing in, and on, Him begins with faith, faith sustains that belief, and faith alone will reveal the grace which saves us. That "faith" is not a "blind" faith. We are without excuse, says the author. God has manifest Himself in all that is before us. Yet, we demand other "hard" evidence ...and miss the forest for the trees.
This may be the answer to questoin 'b.' as well. In our quest for truth, and nothing but truth .....we devise our own standards of what the evidence, the proof, the truth really is. Therefore, we suppress the truth which is already before our very eyes.
Maybe we should search less ...and believe more.