Knowledge is knowing there are aliens on some distant star. Faith is not knowing and building a ship to go find them anyway.
If you know something there is no need for faith. But then if you know something there is no room for trust or hope. If you KNOW there are aliens. Or if you KNOW there is or is not a God there is no reason to question what moral decisions to make. This fundamentally undermines things like free will. But the process of exercising free will is the exercise in question. If you were God why would you corrupt the development of a sentient species by obstructing their development of faith or exercise of free will by revealing your existence to them? It is the pursuit of the unknown that matters. If we KNOW aliens exist then we no longer question whether they exist but rather move onto the next question of what to do now. If we could quantify the divine would it be the divine anymore? Moreover if we could quanitfy the divine what would be the next question? Do we continue to worship it? Do we become it? Do we meld with it? And why does any of this matter? If we are to become divine, or transcend it, or meld with it, or play with it, make love to it, or fight it, then what’s stopping us from doing that now? If we were to find aliens what is the next question? How would we treat them? Or perhaps a better question: How would we treat them DIFFERENTLY than we do other humans on Earth? Or would we and why or why not?
There are many who would argue that a belief in the divine is foolish. That it is ridiculous to believe in something that can’t be proven or quantified. But it all depends on what one places one’s faith in. Yes there are those willing to do terrible things in the name of religion. There are also those willing to do terrible things because they were “just doing their job.” Religion doesn’t make you moral but neither does a lack of it. And placing your faith in a flag can be more deadly than bending knee at the altar of any number of dark Gods and Goddesses. We tend to choose our deities and spiritual practices based on our values. So if you don’t KNOW if there is something out there but believe and have faith there is then you are seeking out something you value and are seeking after. If you are looking for aliens then you value exploration and desire that humans not be the only sentient species in the known universe even if you don’t know if they are or not. So you take your ship and go look for aliens even if you don’t know they exist or not. If you believe in a set of values and place your faith in a given deity you are seeking after those values even if you don’t know explicitly if that deity exists or not, you believe in them and have faith in them, because of the values you hold.