In our responsorial psalm we heard, “With joy you will draw water from the fountain of salvation” (Is 12:3). The Christian story locates that fountain in the Sacrament of Baptism, where for the first time we concretely experience, where we see, hear, and feel (and perhaps taste) the water that signifies and accomplishes salvation.
To be more precise as to what Baptism does: it makes us children of God, heirs of heaven, temples of the Holy Spirit, and members of the Church. It frees us from the original sin and (in the case of adults) from personal sins committed beforehand. It plants in us the seeds of faith, hope, and love—the “theological virtues” that dispose us to divine realities that both lie beyond this world and permeate this world.
Baptism moves us to continue in the path of grace (1) by activating the gifts of the Holy Spirit (viz., wisdom, understanding, right judgment, courage, knowledge, reverence, and fear of the Lord) and (2) by acting in accord with the human virtues of prudence, justice, temperance, and fortitude. And that “path of grace” continues in us when we receive the sacraments that complete our Christian initiation (Confirmation and, in an ongoing way, Holy Eucharist), as well as the sacrament that continually repairs and renews our relationship with God and neighbor (Penance). And without Baptism, we cannot invest our lives in the Sacraments of Marriage or Holy Orders, or in consecrated religious life. So it’s pretty much the key to everything.
Now what John the Baptist was doing wasn’t Christian Baptism, insofar as Jesus hadn’t yet appeared on the scene. You might say that, because of its focus on sorrow for the past and commitment to the future, it was the next best thing; but, as their old commercials used to say, “When you’re out of Schlitz, you’re out of beer.”
The curious thing is, when Jesus did appear on the scene and met His saintly prophetic cousin, He didn’t seem to co-opt John’s baptism into His own. As it turned out, John continued to have disciples of his own for some time. Recall the incident when some of Jesus’ purported enemies were objecting to how His disciples were conducting themselves in contrast to John’s. Jesus assured them that the two camps were not opposed to one another, but that the Best Man and fellow groomsmen certainly would be fulfilled (and, one might infer, more joyful) by attending to the Bridegroom. As the former himself said, “One mightier than I is coming…He will baptize you with the Holy Spirit and fire.”
And, if we are open to it, by the fire of His love He will separate the chaff from the wheat in us, the sin from the grace. For our life’s duration they will co-exist to various degrees in various respects. But our intentional movement along the Baptismal Voyage contains within itself the promise of Our Lord’s Presence—the same Presence He promised to the Apostles when He said, “I am with you always, even to the end of the world” (Mt 28:20).