In the Gospel according to St. Luke (17:12-19), we read an interesting account of Christ walking somewhere between Galilee and Samaria (17:11) and there being encountered by 10 men who were lepers.
Then as He entered a certain village, there met Him ten men who were lepers, who stood afar off. And they lifted up their voices and said, “Jesus, Master, have mercy on us!” So when He saw them, He said to them, “Go, show yourselves to the priests.” And so it was that as they went, they were cleansed. And one of them, when he saw that he was healed, returned, and with a loud voice glorified God, and fell down on his face at His feet, giving Him thanks. And he was a Samaritan. So Jesus answered and said, “Were there not ten cleansed? But where are the nine? Were there not any found who returned to give glory to God except this foreigner? And He said to him, “Arise, go your way. Your faith has made you well.”
St. Gregory Palamas (d. 1359AD) preaching on the Gospel text sees the ten leprosy as being a sign of the sin present in all of humanity. Sin has left humans suffering, full of shame, “ugly, disgusting and unnatural”. As a result of sinful even human nature is perverted and humans have become isolated and alienated from one another. There is a very close relationship between sin and disease. Salvation and health are interrelated.
“As the evangelist Luke will tell us today, when the Lord was going up to Jerusalem, as He was entering a certain town on the way, ten lepers met him ‘which stood afar off: and they lifted up their voices’ (Luke 17:12-13). The evangelist does well to stress that the lepers did not meet Him after He had entered the town, but as He was entering it, because they were driven out of towns and villages as unclean, and lived around the outside of them. They also ‘stood afar off’, since even outside it was not permitted that they should associate with healthy people. They lifted up their voices, meaning they shouted, because of the intervening distance, saying, ‘Jesus, Master, have mercy on us’ (Luke 17:13). See our suffering, see our shame, see the ugly, disgusting and unnatural surface of our skin, for such is leprosy; see the perversion of nature, men’s revulsion, our inconsolable isolation, and in having mercy grant us healing. ‘Jesus, Master, have mercy on us.’ It seems that, although the leper’s words aroused pity, they were not those of men with real faith and understanding, because they call Him ‘Master’, which is not the usual way to address rulers with absolute authority.” (St. Gregory Palamas, The Homilies, p 504)
St. Gregory points out that in the text, the word for “Master” in Greek is not a title of great respect, but rather reveals they think of Jesus as having limited authority – some kind of minor official. They know His name, but don’t understand who He is, and thus show a lack of real faith in Him. Of the ten men healed, one will come back to Jesus, having his understanding of Christ completely changed. Whereas in his initial encounter with Christ, the leper saw Jesus as some kind of minor authority, once he is healed the leper worships Christ and thanks Jesus for healing him. The leper now understands that Jesus is Lord, and that since Jesus has the power of God, Jesus is to be thanked as God. The story thus is not mostly about people being ungrateful even when experiencing a miracle, but rather the story is how one man recognizes the miracle as a sign of who Jesus is: the Messiah and Son of God.