The Bible doesn't ask us to make a leap of faith or have blind faith.
Biblical faith is entrusting ourselves to what we have good reason to believe is true. God didn't ask for blind faith - He gave reason to believe. Here are a couple of examples.
God makes a covenant with Abraham in Genesis 12, which requires Abraham to exercise faith. God reaffirms it in
Genesis 15 and gives Abraham tangible reason to trust Him and the promise. God literally cuts a contract with Abraham according to the custom of the day. Abraham could reflect back on this when circumstances required faith. His faith wasn't blind or wishful, it was based on a contract. We often do things based on contracts - it's a common occurrence in our world. It gives us reason to place our faith in someone else to fulfill their end of the agreement and we act accordingly to keep our end. We invest ourselves, our time, our resources into something because we have faith in the other person due to the contract. In Abraham's case, the contract was unilateral - it was all God's to keep. But the contract gave Abraham reason to trust God.
Fast forward to Matthew 9. Jesus tells a paralytic man that his sins are forgiven. The scribes question Jesus' authority to do this. Jesus didn't answer that they should just trust Him blindly. He healed the man to give them reason to believe He had the authority to forgive sins. Jesus gave a tangible reason to believe what wasn't tangible.
Now every time an exercise of faith is called for, we aren't promised some tangible proof. There's already abundant evidence and reason to place our faith in God. And these are only two examples. Jesus rising from the dead and witnessed by literally hundreds was the penultimate evidence that makes it entirely reasonable to place our faith in Him as Savior.