Rom 10:17 tells us that faith comes by hearing and hearing the revealed word of God.

Hebrews 11:1 AMP
[1] Now faith is the assurance (title deed, confirmation) of things hoped for (divinely guaranteed), and the evidence of things not seen [the conviction of their reality—faith comprehends as fact what cannot be experienced by the physical senses].

Matthew 9:27-30 TPT
[27] As Jesus left the house, two blind men began following him, shouting out over and over, “Son of David, show us mercy and heal us!” [28] And they followed him right into the house where Jesus was staying. So Jesus asked them, “Do you believe that I have the power to restore sight to your eyes?” They replied, “Yes Lord, we believe!” [29] Then Jesus put his hands over their eyes and said, “You will have what your faith expects!” [30] And instantly their eyes opened—they could see!

Matthew 9:27-31 MSG
[27-28] As Jesus left the house, he was followed by two blind men crying out, “Mercy, Son of David! Mercy on us!” When Jesus got home, the blind men went in with him. Jesus said to them, “Do you really believe I can do this?” They said, “Why, yes, Master!” [29-30] He touched their eyes and said, “Become what you believe.” It happened. They saw.