We have a tendency to privatize our fear, our thoughts, and our faith. We tend think they have no life outside of our minds and our hearts. Contrary to this is what Matthew writes here in the Gospel for Trinity 19. Faith is seen. Thoughts are seen. Fear is seen. Ideas have consequences. These are not private things. They are public: perceived and known.
"Jesus, seeing (ἰδὼν) their faith, said, 'Take heart, my son, your sins are forgiven.'" The question is what does Jesus see? Is He seeing into their hearts? To be sure, Jesus can see into their hearts, but is that what is being referred to here. Or does He see the action of the men who bring the paralyzed man to Him?
Perhaps the exchange with the scribes gives us clarity. "And behold, some of the scribes said to themselves, 'This man is blaspheming.' But Jesus, knowing their thoughts, said, 'Why do you think evil in your hearts?'" It seems clear here. But the word for "knowing" here is actually the word for seeing (ἰδὼν). Furthermore, the translation assumes that some of the scribes say this privately, that is, silently to themselves. But the part for "to themselves" can just as naturally mean "among themselves" (ἐν ἑαυτοῖς). So that, in reaction to our Lord's statement that the man's sins are forgiven, some of the scribes lean in together with befuddled expressions on their faces, saying among themselves "This man is blaspheming." So what does Jesus see? Does He see into their minds and hearts here? Or does He see their reaction and their corner winkle?
Finally, the people are afraid because of what they have just seen, namely the Son of Man prove His authority to forgive sins on earth. And that holy fear works doxology in those people. They leave glorifying God.
Frankly, I don't know of any commentary that says Jesus sees the action produced by either the faith or the evil thoughts. But considering the tendency today to privatize faith, to make it matter of personal taste, something that is just between me and Jesus no matter where I am or where Jesus has promised to be, makes this interaction ripe for the picking.
Faith is seen. Thoughts are seen. Fear is seen.
Faith actively trusts, and that produces something in the one who trusts. It produces the bringing of those who need help to Jesus, the only one who can help.
Thoughts are seen because ideas have consequences. The evil thoughts of those scribes was evident by their ad hoc committee meeting discussing the blasphemy of Jesus.
Fear is seen in the enactment of doxology to God for His work in forgiving sins on earth.
Lest we think that all this is private. That no one can see our faith. That no one can see our thoughts. That no one can see whom we fear. Lest we think we can hide the breaking of the First and Greatest Commandment--to fear, love, and trust in God above all things, with our whole being, in heart, mind, soul, and strength. These things are seen.
So what does Jesus see in you? Consider your life in light of the First and Greatest Commandment. What does He see?
He sees a broken, sick, and dying sinner. And seeing this, He says, "Take heart, your sins are forgiven."