"Do you believe that I can do this?" (v. 28)
Jesus asked this question to test the faith of the two blind men. The faith that Jesus wanted to see in them is their faith in Him, in what He claims to be and in what He did. By addressing Jesus as Son of David, they had confessed their faith in Him. By responding, "Lord, we do." (v.29), they reaffirm their faith in Jesus by calling Him, "Lord". So, Jesus removed their blindness.
By this the evangelist, Matthew pointed out that faith in Jesus is a pre-requisite for receiving healing. Though warned not to tell anyone about this, they continued to spread Jesus fame throughout the district.
The joy that the two blind men experienced is re-iterated in the first reading wherein Prophet Isaiah described what the 'new world' would be liked. This is what we long for in our world today. Confronted with so much of pain and suffering in various forms throughout the world, Jesus wants to assure us that when faced situations of helplessness, hopelessness, fears, doubts etc., we are to turn to Jesus and trust Him that He will relieve us of such. Do we have such faith or do we want to have instant cure and solutions to our problems?
"Lord, help us to increase our faith in You; in all things help us to persevere and wait for Your coming with trust and love."