What does that even mean, beyond that you decide a path's worth starting out on - experimenting with - without knowing in advance the final destination, like any human endeavour or study or relationship?
Without reading the thread again, I think we were talking about morality being grounded in religious belief. So I meant 'leap of faith' in that you cannot empirically prove the existence of God and it's a leap of faith to believe the stuff in the Bible. It's a phrase originated by the Danish philosopher Kierkegaard.
If you are taking your moral stance from Biblical teaching you have to choose to presuppose the truth of God's existence in the first place.
I find it quite interesting that scientists especially are able to do this. There are outstanding modern scientists, including ones who work for NASA, who are able to maintain their religious belief alongside a scientific mindset that demands hypotheses, evidence, proof etc. in their daily work. I am guessing that they are mostly people who grew up in their faith, rather than converts, and who can somehow reconcile their cultural upbringing with scientific methodology.
I suppose it shouldn't be that surprising. Many people, including doctors and scientists , will discount evidence when it doesn't agree with their own ideology. You see it in things like intelligence and race, homeopathy, and whether sex is binary.