I concur that evangelicals would not be considered “humble’ because they are proclaiming something—proclaiming it to be the most important decision you will ever make. And they will indeed offer plenty of evidence for it.
Evangelical Christians and organized Atheists both PROCLAIM something about God—the Evangelical often offers some sort of evidence and the Atheist in turn declares there are NO evidences to support the claims of the Christian. Neither is a “humble’ position.
A humble Atheist would be someone who kindly, comfortingly, assures a person that this life, in all its good and in all its pain and suffering—is all there is. That is not to say that it is meaningless. And at death—all but love survives, and memories—kind of bittersweet. Even though there is no god, we are all still significant to each other and in the grand scheme of things.
The kind of Christian you are describing in your question who accepts things on faith and considers this ‘humble’—well, that is the Christian who accepts the Bible as the word of God and doesn’t need empirical evidences or tries to prove anything. They may have already seen enough ‘evidences’—or maybe just accept it on faith.
To state that you know (as many Christians).or that you merely believe, or don’t know (as an agnostic) is not in and of itself humble. It is merely stating one’s belief or position.
And it is not arrogant to proclaim Christ is the only way to God if it is true—or if one is convinced it is true. Like the message or not, such people are concerned about your eternal destiny.
As for me, I am convinced that we ALL have access to the same information But I do not hesitate to state my own position