In order to even do science we must first make certain non-falsifiable assumptions, fundamentally. This is a basic point of metaphysics and epistemology.
To quote from Mike Alder's Newton's Flaming Laser Sword
> It must also be said that, although one might much admire a genuine Newtonian philosopher if such could found, it would be unwise to invite one to a dinner party. Unwilling to discuss anything unless he understood it to a depth that most people never attain on anything, he would be a notably poor conversationalist. We can safely say that he would have no opinions on religion or politics, and his views on sex would tend either to the very theoretical or to the decidedly empirical, thus more or less ruling out discussion on anything of general interest. Not even Newton was a complete Newtonian, and it may be doubted if life generally offers the luxury of not having an opinion on anything that cannot be reduced to predicate calculus plus certified observation statements. While the Newtonian insistence on ensuring that any statement is testable by observation (or has logical consequences which are so testable) undoubtedly cuts out the crap, it also seems to cut out almost everything else as well.
You wall off the non-falsifiable stuff in a box labeled "not science" and focus on the stuff that is falsifiable.
That is not necessarily a bad thing.
It's something that human consciousness seemingly has to do.
Science doesn't care about which ones you pick. You can be doing science with any set of initial non-falsifiable assumptions that humans are capable of holding.