Dear brothers and sisters!
[...] in his public life Jesus healed many sick people, revealing that God wants life for human beings, life in its fullness. This Gospel (Mk 1:40-45) shows us Jesus in touch with a form of disease then considered the most serious, so serious as to make the person infected with it “unclean” and to exclude that person from social relations: we are speaking of leprosy. Special legislation (cf. Lev 13-14) allocated to priests the task of declaring a person to be “leprous”, that is, unclean; and it was likewise the priest’s task to note the person’s recovery and to readmit him or her, when restored to health, to normal life.
While Jesus was going about the villages of Galilee preaching, a leper came up and besought him: “If you will, you can make me clean”. Jesus did not shun contact with that man; on the contrary, impelled by deep participation in his condition, he stretched out his hand and touched the man — overcoming the legal prohibition — and said to him: “I will; be clean”.
That gesture and those words of Christ contain the whole history of salvation, they embody God’s will to heal us, to purify us from the illness that disfigures us and ruins our relationships. In that contact between Jesus’ hand and the leper, every barrier between God and human impurity, between the Sacred and its opposite, was pulled down. This was not of course in order to deny evil and its negative power, but to demonstrate that God’s love is stronger than all illness, even in its most contagious and horrible form. Jesus took upon himself our infirmities, he made himself “a leper” so that we might be cleansed.
A splendid existential comment on this Gospel is the well known experience of St Francis of Assisi, which he sums up at the beginning of his Testament: “This is how the Lord gave me, Brother Francis, the power to do penance. When I was in sin the sight of lepers was too bitter for me. And the Lord himself led me among them, and I pitied and helped them. And when I left them I discovered that what had seemed bitter to me was changed into sweetness in my soul and body. And shortly afterward I rose and left the world” (FF, 110).
In those lepers whom Francis met when he was still “in sin” — as he says — Jesus was present; and when Francis approached one of them, overcoming his own disgust, he embraced him, Jesus healed him from his “leprosy”, namely, from his pride, and converted him to love of God. This is Christ’s victory which is our profound healing and our resurrection to new life!
[Pope Benedict, Angelus 12 February 2012]