When Jesus had come down from the mountain, great crowds followed him; and there was a leper who came to him and knelt before him, saying, "Lord, if you choose, you can make me clean." He stretched out his hand and touched him, saying, "I do choose. Be made clean!" Immediately his leprosy was cleansed. Then Jesus said to him, "See that you say nothing to anyone; but go, show yourself to the priest, and offer the gift that Moses commanded, as a testimony to them."
When he entered Capernaum, a centurion came to him, appealing to himand saying, "Lord, my servant is lying at home paralysed, in terrible distress." And he said to him, "I will come and cure him." The centurion answered, "Lord, I am not worthy to have you come under my roof; but only speak the word, and my servant will be healed. For I also am a man under authority, with soldiers under me; and I say to one, 'Go,' and he goes, and to another, 'Come,' and he comes, and to my slave, 'Do this,' and the slave does it." When Jesus heard him, he was amazed and said to those who followed him, "Truly I tell you, in no one in Israel have I found such faith. I tell you, many will come from east and west and will eat with Abraham and Isaac and Jacob in the kingdom of heaven, while the heirs of the kingdom will be thrown into the outer darkness, where there will be weeping and gnashing of teeth." And to the centurion Jesus said, "Go; let it be done for you according to your faith." And the servant was healed in that hour.
This passage from the Gospel of Matthew is really two separate pieces, so let's consider them one at a time—and see if there's a single message beneath both.
Jesus' healing of the leper is simple and transparent. The leper has total faith in Jesus' ability to heal him of his disease, and he is healed. Jesus then uses this event to illustrate that there is no conflict between the law of Moses and the more loving understanding he teaches. He tells the leper to obey the law by presenting himself to the temple with a gift of gratitude for the priest.
A similar question of faith underlies the story of the centurion's servant. Assuming that his physical presence would be expected, Jesus agrees to go. But the centurion, a "pagan" upholding the hated Roman rule, surprised him by demonstrating more faith than that. "Only speak the word, and my servant will be healed." And it is so. Here it is not the law of Moses but the universal law of Spirit that creates the environment in which the healing can happen.
So the two different stories represent two different approaches to the question of healing. One lies through the "law of Moses;" the other through universal spiritual principle. Jesus, I think, wants to make the point that the Truth he teaches does not break with the Law, but rather emphasizes the common energy of love and faith.