"According to your faith, let it be done to you." Faith is confidence. Faith is certainty. Faith is being sure. It is not dipping the toe in before leaping in. It is not closing eyes expecting the worst when reaching the hand in. Faith is a leap.
Jesus came preaching "Repent, for the kingdom of heaven is near." The evidence that this is true is changed lives. When the kingdom of heaven arrives in people's lives, they are changed. Jesus teaches through his words and deeds that the kingdom seeks to change people from the inside out and not from the outside in.
Typical man-made religions seek to do this. If we do the right things, say the right things, and present ourselves to others in the right way, we will win God's favour. Then, and only then, will we gain the "spiritual" reward that the chief deity has in store for his/her "enlightened".
Jesus teaches, however, that changed lives only occur when it's from the inside out. This is why he seeks the broken-hearted. God doesn't look at the things man looks at. "Man looks at the outward appearance, but God looks at the heart." How do we become the people we dream of being? How do we become the people who are worthy to bear the image of the Most High God? How do we become the people we have been created to be? Whose kingdom will we put our trust in? Ours? How is that working for us? Are we ready to be subject to the King of kings and the Lord of lords?
These two blind men knew who Jesus is. By calling him the son of David, they acknowledge him as the descendant of David who was to reign forever over God's people. They further reinforce this by calling him Lord. They demonstrate this by their actions by continuing to call out to him and following him inside. They confirm their faith by answering Jesus' question in the affirmative.
The friends of the demon-possessed mute knew this as well. They knew that Jesus could help their enslaved friend. And Jesus honors their faith. And those without faith try to explain it away using the reason available to the truly blind.
"Repent, for the kingdom of heaven is near." What followers of Jesus realise is that we do not the work of change; God does. He works with those who see the tattered state of their kingdom and are ready to give complete surrender to the kingdom of heaven.
"According to your faith, let it be done to you."