“According to your faith be it done to you.” (Mt 9:29b)
All through the gospels we see that Jesus responds to faith. Jesus is moved to action when he sees the faith of those who come to him. He rewards those who demonstrate their faith by pressing in or crying out to him, and he rebuked those who demonstrated a lack of faith by the doubts they confessed.
Faith is crucial, of that there is no doubt! The writer to the Hebrews tells us that "Without faith it is impossible to please God." He also goes on to tell us why:
For whoever would draw near to God must believe that he exists and that he rewards those who seek him. (Heb 11:6)
This gives us a correct understanding of how we interact with God by faith. Our faith does not constrain God - he is able to do immeasurably more than all we can ask or imagine. He managed to create a whole Universe just fine before we came along. Our faith does not manipulate God - it is he that is sovereign, not us. We cannot twist his arm by pumping up how much we "believe" something is going to happen. In fact faith does not draw God to us at all (he is within us already!) it is the means by which we draw near to God.
We see that in Matthew 9, in several examples: The men who brought Jesus the paralytic on the mat - Jesus saw their faith. The woman who touched the hem of his garment - Jesus said her faith had made her well. And the two blind men who cried out to Jesus to be healed - Jesus said it would be unto them according to their faith.
What was their faith? In each case it was the fact they pressed into Jesus for what they needed. It was exactly the kind of faith described in Hebrews 11:6. They believed who he was, and they earnestly sought him as the one who was able to meet their needs. Faith is not static. It is not self-sufficiency. It is best displayed in the lives of those who are drawing ever closer to Jesus. Those who recognise that he is who he claims to be and who make demands on him for what is needed.
Jesus is not bothered by such demands made in faith. He delights to respond to them. Indeed he seems to be much more bothered when they are absent!