According to this idea there are "two" baptism, one in water and one in the Spirit. However, in order to understand the Lord Jesus' words it is first necessary to understand that He referred to only one birth and not two. Sir Robert Anderson wrote:
"Now, first it is essential to notice that this is not a twofold birth (of water, and of the Spirit), but emphatically one - a birth of water-and-Spirit, in contrast with the birth which is of flesh. This is not obvious in a translation; but in the original it is unmistakable. And the context emphasises it, for in the very next sentence, and again in verse 8, the water is omitted altogether, and the new man is spoken of merely as 'born of the Spirit.' It follows, therefore, that whatever the water signifies it must be implied in the words "born of the Spirit," and every one who has been "born anew" has been "born of water and the Spirit" (Ibid., p.222).
Robert V. McCabe agrees, writing that
"in v. 5 the preposition 'ek' governs two nouns, 'hydor' and 'pneuma,' that are coordinated by 'kai.' This indicates that Jesus regards 'hydor kai pneuma' as a conceptual unity. If 'hydor kai pneuma' is a conceptual unity, this phrase may be taken either as a 'water-spirit' source or a 'water-and-Spirit' source of birth. A good case can be presented for either view in the context of John 3:1–8. With either view, there is one birth that is characterized either as 'water-spirit,' or 'water-and-Spirit.' Neither of these understandings suggest that there are two births, physical and spiritual" [
emphasis added] (McCabe, "The Meaning of 'Born of Water and the Spirit' in John 3:5,"
Detroit Baptist Seminary Journal [Fall 1999], p.85-107).
From this we can understand that the new birth was accomplished by the gospel that comes in the power of the Holy Spirit. Here the Apostle Peter referred to both elements:
"...by them that have preached the gospel unto you with the Holy Spirit sent down from heaven...Being born again, not of corruptible seed, but of incorruptible, by the word of God...this is the word which by the gospel is preached unto you" (1 Pet,1:12,23,25).