We don't know which unanswered questions if any will never be answered. There may or might not be eternally unanswerable questions
It's probably more helpful to think not so much in terms of the ultimate truth of ideas, but rather their utility. Ideas that can be reliably used to predict and at times control outcomes are useful ideas, and can be called facts, the collection of which can be called knowledge. Newton's work was used to take man to the moon and back even though as Einstein showed us, it was not "absolutely correct 100%." That needn't concern us or distract us.
No, honesty and clear-headedness.
An unbeliever is generally a skeptic, meaning that he needs a sound reason to believe anything before believing it.
Skepticism is one of the greatest ideas man has ever conceived - up there with things like empiricism and justice. It's been an incredibly useful idea, forcing us to reconsider received wisdom and toss out the ideas that just don't work or can be shown to be wrong. With that in mind, alchemy became chemistry and astrology became astronomy. Faith based systems of thought became evidence based ones, and went from being useless to useful. That's a pretty strong endorsement of skepticism.
Aren't you happy that a few centuries ago, skeptics rejected the received biblical wisdom that kings were divinely appointed, and that failing to submit to their authority was rebellion against God and therefore a damnable offense? I hope you wouldn't call America's founders dishonest or blind-hearted for not believing the following:
- "Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves."- Romans 13:1-2
There is no reason to believe that. If you do, you are at risk of supporting despots. If you believed such a thing and you lived during the Revolutionary War, you would be obligated to fight for the king, right? The king is God's agent on earth.
Skepticism was the only path to tunneling out and creating an enlightened form of government - yet another great achievement born of skepticism, and another strong endorsement of the principle and its practice.
We can see the benefit of questioning and empirically testing all received wisdom, keeping only that which proves useful. We've discussed what happens when one applies skepticism to matters of physical reality and daily life / government. We get science and the modern liberal democratic state with limited government and guaranteed individual rights. Life becomes better.
If one applies skepticism to god claims, one is an unbeliever. That's not an assertion that gods don't exist - just that we have insufficient evidence that they do, and that therefore one should not believe any god claims unless that changes. I'd call that a more honest position, not a dishonest one.