And as Jesus passed on from there, two blind men followed (him), crying out, "Son of David, have pity on us!" When he entered the house, the blind men approached him and Jesus said to them, "Do you believe that I can do this?" "Yes, Lord," they said to him. Then he touched their eyes and said, "Let it be done for you according to your faith." And their eyes were opened. Jesus warned them sternly, "See that no one knows about this." But they went out and spread word of him through all that land. (Mt 9:27-31)
Two blind men followed him. They did not follow him to be his disciples. They wanted a miracle from him. They wanted to be healed. ("Do you believe that I can do this?" "Yes, Lord," they said to him). They believed in him and they prayed to him (Son of David, have pity on us!). Interestingly the blind men (who could not see anything and could not see the path) followed him. Their faith together with prayer was seen in their effort.
Their faith was rewarded (Let it be done for you according to your faith). Jesus heard their cry (prayer) and he saw their effort (followed him) and rewarded their faith. It is the faith that matters for divine revelation and divine response. Here, in this passage, the faith is seen in their acknowledgement that God is present in Jesus and active in Jesus.
Anyone who experiences God will not keep quiet. He would rather run out and spread around the news that God is present and active. This is what we see in these two blind men. Even when they are constrained and warned they could not resist proclaiming the presence of God. (I say to myself, I will not mention him, I will speak in his name no more. But then it becomes like fire burning in my heart, imprisoned in my bones; I grow weary holding it in, I cannot endure it. Jer 20:9)