“Born again ” The Bible way
The only biblical use of the term “born again” occurs in John 3:3-5 — although, as we shall see, similar and related expressions such as “new birth” and ,regeneration” occur elsewhere in Scripture (Titus 3:5; 1 Pet 1:3, 23). In John 3:3, Jesus tells Nicodemus, “Truly, truly, I say to you, unless one is born again, he cannot see the kingdom of God.” The Greek expression translated “born again” (gennathei anothen) also means “born from above.” Jesus, it seems, makes a play on words with Nicodemus, contrasting earthly life, or what theologians would later dub natural life (“what is born of flesh”), with the new life of heaven, or what they would later call supernatural life (“what is born of Spirit”).
Nicodemus’ reply: “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” (John 3:4). Does he simply mistake Jesus to be speaking literally or is Nicodemus himself answering figuratively, meaning, “How can an old man learn new ways as if he were a child again?” We cannot say for sure, but in any case Jesus answers, “Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, `You must be born again.”’ (John 3:5-7).
Here Jesus equates “born again” or “born from above” with “born of water and the Spirit.” If, as the Catholic Church has always held, being “born of water and the Spirit” refers to baptism, then it follows that being “born again” or “born from above” means being baptized.
Clearly, the context implies that born of “water and the Spirit” refers to baptism. The Evangelist tells us that immediately after talking with Nicodemus, Jesus took his disciples into the wilderness where they baptized people (John 3:22). Furthermore, water is closely linked to the Spirit throughout John’s Gospel (for instance, in Jesus’ encounter with the Samaritan woman at the well in John 4:9-13) and in the Johannine tradition (cf. 1 John 5:7). It seems reasonable, then, to conclude that John the Evangelist understands Jesus’ words about being “born again” and “born of water and the Spirit” to have a sacramental, baptismal meaning.
Read the full article here (Are Catholics Born Again? By Mark Brumley)