What is Baptism anyway? Of course John Baptized Jesus at the beginning of his public ministry. From a Catholic perspective:
1226 of the Catholic Catechism:
From the very day of Pentecost the Church has celebrated and administered holy Baptism. Indeed St. Peter declares to the crowd astounded by his preaching: "Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit." Acts 2:38 The apostles and their collaborators offer Baptism to anyone who believed in Jesus: Jews, the God-fearing, pagans. Always Baptism is seen as connected with faith: "Believe in the Lord Jesus, and you will be saved, you and your household," St. Paul declared to his jailer in Philippi. And the narrative continues, the jailer "was baptized at once, with all his family." Acts 16:31-33
1229 Christian Initiation
From the time of the apostles, becoming a Christian has been accomplished by a journey and initiation in several stages. This journey can be covered rapidly or slowly, but certain essential elements will always have to be present: proclamation of the Word, acceptance of the Gospel entailing conversion, profession of faith, Baptism itself, the outpouring of the Holy Spirit, and admission to Eucharistic communion.
1231
Where infant Baptism has become the form in which this sacrament is usually celebrated, it has become a single act encapsulating the preparatory stages of Christian initiation in a very abridged way. By its very nature infant Baptism requires a post-baptismal catechumenate. Not only is there a need for instruction after Baptism, but also for the necessary flowering of baptismal grace in personal growth. The catechism has its proper place here.
1265
Baptism not only purifies from all sins, but also makes the neophyte "a new creature", an adopted child of God, who has become a "partaker of the divine nature," member of Christ and co-heir with him and a temple of the Holy Spirit.
1266
The Most Holy Trinity gives the baptized sanctifying grace, the grace of justification:
- enabling them to believe in God, to hope in him, and to love him through the theological virtues;
- giving them the power to live and act under the prompting of the Holy Spirit through the gifts of the Holy Spirit;
- allowing them to grow in goodness through the moral virtues.
Thus the whole organism of the Christian's supernatural life has its roots in Baptism.
I know this is a lot to quote and post! The information and teaching from scripture and tradition goes on for pages so this is just a small summary. The last bolded line though I think makes clear how Baptism is such an essential aspect in the Christian life, at least from a Catholic viewpoint.
Is the Anglican tradition so different?
It is the first of a series of sacraments of initiation in the Catholic church - so definitely Christian and not just a secular rite of passage.