One key Scripture reference to being "born again" or "regenerated" is John 3:5, where Jesus says, "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God."
This verse is so important that those who say baptism is just a symbol must deny that Jesus here refers to baptism. "Born again" Christians claim the "water" is the preached word of God.
Few truths are so clearly taught in the New Testament as the doctrine that in baptism God gives us grace. Again and again the sacred writers tell us that it is in baptism that we are saved, buried with Christ, incorporated into his body, washed of our sins, regenerated, cleansed, and so on (see Acts 2:38, 22:16; Rom. 6:1–4; 1 Cor. 6:11, 12:13; Gal. 3:26–27; Eph. 5:25-27; Col. 2:11–12; Titus 3:5; 1 Pet. 3:18–22). They are unanimous in speaking of baptism in invariably efficient terms, as really bringing about a spiritual effect.
Although Latin-rite Catholics are usually baptized by infusion (pouring), they know that immersion (dunking) and sprinkling are also valid ways to baptize. Fundamentalists, however, regard only baptism by immersion as true baptism, concluding that most Catholics are not validly baptized at all.
Although many Protestant traditions baptize babies, Baptists—and "Bible churches" in the Baptist tradition—insist that baptism is only for those who have come to faith. Nowhere in the New Testament, they point out, do we read of infants being baptized.
Fundamentalists often criticize the Catholic Church’s practice of baptizing infants. According to them, baptism is for adults and older children, because it is to be administered only after one has undergone a "born again" experience—that is, after one has "accepted Jesus Christ as his personal Lord and Savior." At the instant of acceptance, when he is "born again," the adult becomes a Christian, and his salvation is assured forever. Baptism follows, though it has no actual salvific value.
Christians have always interpreted the Bible literally when it declares, "Baptism . . . now saves you, not as a removal of dirt from the body, but as an appeal to God for a clear conscience, through the resurrection of Jesus Christ" (1 Pet. 3:21; cf. Acts 2:38, 22:16, Rom. 6:3–4, Col. 2:11–12).
If you took your parish’s catechism classes when you were growing up, you at least remember that there are two kinds of grace, sanctifying and actual. That may be all you recall. The names being so similar, you might have the impression sanctifying grace is nearly identical to actual grace. Not so.
Sanctifying grace stays in the soul. It’s what makes the soul holy; it gives the soul supernatural life. More properly, it is supernatural life.
There are few more confusing topics than salvation. It goes beyond the standard question posed by Fundamentalists: "Have you been saved?" What the question also means is: "Don’t you wish you had the assurance of salvation?" Evangelicals and Fundamentalists think they do have such an absolute assurance.
~ Thomas Aquinas; philosopher, theologian, author, Doctor of the Church, patron of Catholic universities, colleges, and schools; reaffirming his total submission to the authority of the Church from his deathbed