Now the people were filled with expectation,
and all were asking in their hearts
whether John might be the Christ.
The Baptist answered them all, saying,
“I am baptizing you with water,
but One mightier than I is coming.
I am not worthy to loosen the thongs of His sandals.
He will baptize you with the Holy Spirit and fire.
His winnowing fan is in His hand to clear His threshing floor
and to gather the wheat into His barn,
but the chaff He will burn with unquenchable fire.”
Exhorting them in many other ways,
he preached good news to the people.
Born into the priestly class as a descendant of Aaron, John the Baptist would have been instructed in priestly duties and would have known the Temple well. Indeed, his very birth was announced by God's messenger to his father in the Temple when he was serving as priest. However, instead of serving in the Temple, John's ministry was conducted in the desert, where the people of Israel began after being led out of bondage in Egypt and where the Lord appeared to them and made His covenant with them.
There was a reason that John went out into the desert wilderness. In order to see him, the people were required to return to that desert. And there was a reason that John baptized in the Jordan River, the place where the people of Israel had crossed into the promised land, led by Joshua. John's ministry and baptism of repentence was a call for the people to reaffirm their identity, to reaffirm their fidelity to God, by going back into the desert, where they relied totally on God for their very sustenance and survival, so as to symbolically reenter the Promised Land through water, leaving behind sin and death. It was a new Exodus, but instead of bondage in Egypt, they were led out of the bondage of sin and death into new life.
Jesus of Nazareth (2007)
Pope Benedict XVI
The Baptist’s appearance on the scene was something completely new. The Baptism that he enjoined is different from the usual religious ablutions. It cannot be repeated, and it is meant to be the concrete enactment of a conversion that gives the whole of life a new direction forever. It is connected with an ardent call to a new way of thinking and acting, but above all with the proclamation of God’s judgment and with the announcement that one greater than John is to come. The Fourth Gospel tells us that the Baptist “did not know” (cf. Jn 1:30-33) this greater personage whose way he was to prepare. But he does know that his own role is to prepare a path for this mysterious Other, that his whole mission is directed toward him. * * *
We can imagine the extraordinary impression that the figure and message of John the Baptist must have produced in the highly charged atmosphere of Jerusalem at that particular moment of history. At last there was a prophet again, and his life marked him out as such. God’s hand was at last plainly acting in history again. John baptizes with water, but one even greater, who will baptize with the Holy Spirit and fire, is already at the door. Given all this, there is absolutely no reason to suppose that Mark is exaggerating when he reports that “there went out to him all the country of Judea, and all the people of Jerusalem; and they were baptized by him in the river Jordan, confessing their sins” (Mk 1:5). John’s baptism includes the confession of sins. * * * The goal is truly to leave behind the sinful life one has led until now and to start out on the path to a new, changed life.
The actual ritual of Baptism symbolizes this. On one hand, immersion into the waters is a symbol of death, which recalls the death symbolism of the annihilating, destructive power of the ocean flood. The ancient mind perceived the ocean as a permanent threat to the cosmos, to the earth; it was the primeval flood that might submerge all life. The river (Jordan) could also assume this symbolic value for those who were immersed in it. But the flowing waters of the river are above all a symbol of life. The great rivers—the Nile, the Euphrates, the Tigris—are the great givers of life. The Jordan, too, is—even today—a source of life for the surrounding region. Immersion in the water is about purification, about liberation from the filth of the past that burdens and distorts life—it is about beginning again, and that means it is about death and resurrection, about starting life over again anew. So we could say that it is about rebirth. * * *