In Matthew 9:28, Jesus asks the two blind men seeking healing, "Do you believe that I am able to do this?" Christ's challenge concerns their faith. If faith is present, miraculous healing will occur according to God's will. If it is absent, God will grant no healing. A person of faith receives preferential treatment, and in fact, faith is so important to God that His Word declares, "Without faith it is impossible to please Him" (Hebrews 11:6).
The blind men answer Christ's challenge with outstanding, genuine faith, saying, "Yes, Lord." In the Greek, this is a strong affirmation, carrying a tone of certainty. The men had no doubt that Christ could heal them, unlike many people today. They believed Jesus was the son of David, indicating that, though they were blind, God had begun to open their minds.
These men faced many disadvantages that worked against producing faith, but they still trusted Christ in impressive ways. Those who—unjustifiably—excuse their lack of faith because of life's difficulties hinder their spiritual growth. Many with handicaps and weaknesses have come to have faithful relationships with Christ.
Martin G. Collins
The Miracles of Jesus Christ: Healing Two Blind Men (Part Two)