Here's Fr. Cantalamessa's (as usual) wonderful reflection on this Sunday's readings (Via Zenit. Emphasis added.)
Glorify God in Your Body
The Gospel passage allows us to be present at the formation of the first nucleus of disciples, from which will first develop the College of Apostles and then the whole Christian community. John is still on the banks of the Jordan River with two of his disciples when he sees Jesus go by and does not hesitate to cry out again: "Behold the Lamb of God!" The two disciples understand, and, leaving the Baptist for good, they start to follow Jesus.
Seeing that they are following him, Jesus turns to them and asks: "What do you seek?" To break the ice, they respond: "Teacher, where are you staying?" "Come and see," he replies. They went, they saw him and that day they stayed with him. That moment became decisive for them in their lives, remembering even the hour it occurred: it was close to four o'clock in the afternoon.
In the second reading, St. Paul illustrates a feature that must characterize the life of Christ's disciple: purity. "The body," he says among other things, "is not meant for immorality, but for the Lord, and the Lord for the body. … So glorify God in your body." Given that it is a topic much discussed and vital for our present-day society, it is worthwhile to give it our attention.
Perhaps those who are able to understand best the subject of purity are precisely those who are truly in love. Sex becomes "impure" when it reduces the other (or one's own body) to an object, a thing, but this is something that true love refuses to do. Many of the excesses taking place in this area are somewhat artificial; they are due to an external imposition dictated by commercial or consumerist motives. It is not, as one is lead to believe, the "spontaneous evolution of customs." It is a guided, imposed evolution.
One of the excuses that contributes most to fostering the sin of impurity in the common mentality and to divest it of all responsibility is the idea that in any case, it harms no one, it does not harm the rights or liberty of others except, it is said, in the case of rape or violation.
But it is not true that the sin of impurity ends with the one who commits it. All abuse, no matter where and who commits it, contaminates man's moral environment, causes an erosion of values and creates what Paul defines "the law of sin," illustrating as he does its terrible power to drag people to ruin (cf. Romans 7:14ff).
The first victims of all this are in fact young people. Phenomena so condemned, such as the exploitation of minors, rape, pedophilia, but also certain atrocities committed not on minors, but by minors -- are not born from nothing. They are, at least in part, the result of the climate of exasperated excitation in which we live and in which the most fragile succumb.
It was not easy, once it began, to stop the mudslide that some time ago struck Sarno and other populations of Campania, destroying them. It was necessary to avoid the felling of trees and other environmental damages that made the mudslide inevitable. The same is true for certain tragedies connected to sex: Having destroyed the natural defenses, the tragedies become inevitable.
But today it is not enough to have a purity based on fears, taboos, prohibitions, the mutual escape of man and woman, as if each one of them were, always and necessarily, a trap for the other and a potential enemy, instead of, as the Bible says, "a help." It is necessary to stress defenses that are no longer external but internal, based on personal convictions. Purity must be cultivated for itself, for the positive value it represents for the individual, and not only because of concerns of health or good name to which its transgression exposes one.
Purity ensures the most precious thing that exists in the world: the possibility to approach God. "Blessed are the pure of heart, for they shall see God," said Jesus. They will not see him just one day, after their death, but already now: In the beauty of creation, of a face, of a work of art; they will see him in their own hearts.