@lykanthrocide @fkq1q2r2 Matthew 28:19-20, Baptism is the first step of being a disciple of Christ.
Mark 16:16, whoever believes and is Baptized shall be saved.
Acts 2:38, Baptism confers the forgiveness of sins which Christ won on the Cross.
Romans 6:1-4, whoever is Baptized is united to Christ in both His death and Resurrection.
Colossians 2:11-12, Baptism replaces circumcision as the means by which one is entered into Christ's Kingdom.

And as we see from Pentecost and the baptism of the Ethiopian in Acts, this means water baptism performed in the Name of the Father and of the Son and of the Holy Spirit. That means that, per John 3:5, Baptism as a Sacrament confers regeneration by virtue of the Holy Spirit's involvement with the rite.

It is the normative way by which people are regenerated, so it is a necessary part of salvation, as St. Peter says plainly in 1 Peter 3:21. There may well be exceptions to the rule, but that only demonstrates the validity of the rule generally.