Występująca w dialogu Jezusa z Nikodemem fraza gennēthḗ(i) eks hýdatos kaí pneúmatos (J 3, 5) ma głębokie znaczenie teologiczne. Jej przesłanie wynika z poszczególnych terminów: hýdōr („woda”), pneúma („duch”), które w tradycji biblijnej posiadają bogatą symbolikę, nabudowaną na ich dosłownym znaczeniu. Teksty ksiąg biblijnych, a zwłaszcza czwarta Ewangelia, ukazują ścisły związek pomiędzy rzeczywistościami, które wyrażają oba terminy. We frazie gennēthḗ(i) eks hýdatos kaí pneúmatos terminy hýdōr i pneúma odnoszą się do tej samej rzeczywistości, czyli duchowych (nadprzyrodzonych) narodzin, których sprawcą jest Duch. Wzmianka o „wodzie” ma za zadanie dookreślenie okoliczności, w których dokonuje się owo „zrodzenie z wody i Ducha”. Okoliczności te zachodzą w kontekście sakramentu chrztu.
The natural qualities of water (hýdōr), discovered especially in the conditions of the Ancient Near East, gave rise to its metaphorical, symbolic presentation in the Old Testament tradition. Giving it, then, means providing someone with life and all kinds of blessings. Theologically, the giving of water symbolizes granting of the blessing that in its entirety was expected in the messianic times. Water acquired a special significance also in the context of ritual washing: washing with water meant spiritual washing, on moral grounds. The Old Testament also shows the connection of water (hýdōr) with the reality of the spirit (pneúma) (see Isa 44:3; Ezek 36:25–27; Joel 3:1–2). In this context, “spirit” (Heb: rûaḥ) was seen as God’s gift to man (Heb: rûaḥ YHWH; rûaḥ ʼĕlōḥîm). The close relationship between “water” and “the Spirit” is set out in the Fourth Gospel (see John 7:37–39). Taking into account the relationship between “water” and “the Spirit” in the context of the entire biblical tradition, especially the Fourth Gospel, it can be assumed that in the phrase: gennēthḗ(i) eks hýdatos kaí pneúmatos, both terms: hýdōr and pneúma, refer to one and the same reality that is, spiritual (supernatural) births caused by the Spirit. The exposed element, which is “water”, is to define the circumstances in which this “birth of water and the Spirit” takes place. These circumstances are present in the sacrament of Baptism. It should be remembered, however, that the description contained in the pericope “Conversations of Jesus with Nicodemus”– as some exegetes noted – should not be treated as an account of the institution of the sacrament of baptism, or of giving details related to the ritual side, because the author of the Fourth Gospel primarily intended to show the effects of the saving action of this sacrament.