16. Seeing the Ephesian unitarians obviously had some sort of doctrine of 'baptism' (cf. the other heterodox group in I Cor. 15:29), Paul next asks them another question (in Acts 19:3). "Unto what, then, were you baptized?" They reply: "Unto John's baptism!" This may mean: 'baptized' belatedly, after the death and exaltation of Jesus (and perhaps even after Pentecost Sunday, yet still ignorant of the Holy Spirit)! Thus Bruce (op. cit. at Acts 19:5-7 n. 12). Or it may even mean: 'baptized' in the name of John — as if he "were the revelation of God" (rank heresy)! Cf. Kuyper's De Sacramentis (within his Dict. Dog. V:134f). Either way, Paul is now convinced these men were not yet Christians — and indeed had not been baptized by John himself, nor even validly, at all! So Paul now evangelizes them (19:4), saying: "John truly baptized, with the baptism of repentance; saying to the people that they should believe in the One coming after him, namely Jesus!" Mt. 3:3-12; Mk. 1:4-8; Lk. 3:3-17; Jh. 1:29-33; 3:23-34. "When they heard this, they were baptized [for the first time ever] in the Name of the Lord Jesus; and when Paul laid his hands on them the Holy Spirit came upon them (eelthe…ep' autois), and they began to speak in languages and to prophesy."
17. All the various 'first-fruit' categories of converts –Jews, Samaritans and heretics — Semites, Hamites and Japhethites — had now been baptized by the Spirit and incorporated by water-baptism into the 'ark' of the Church Visible! Gen. 6:10-18; 7:1-7; 10:1f; I Pet. 3:18-21. On the great significance of this, see Rev. Prof. Dr. Abraham Kuyper's great book The Work of the Holy Spirit (Grand Rapids: Eerdmans, 1941, esp. pp. 123-7). Thus, there are in Scripture no more Spirit-baptisms well-nigh accompanied by miraculous testimony in foreign languages — after Acts 19:1-6. Instead, that was almost immediately followed by the Acts 19:9f final separation of the Spirit-completed and water-baptized Visible Church from the Spirit-depleted and unbaptized Jewish Synagogue (cf. Rev. 2:9 & 3:9). Thenceforth, the Spirit simply engrafts new believers into the Church Visible by water baptism. "He who has believed, and been baptized, shall be saved"; "there is one Spirit…, one baptism"; "keep on being filled in the Spirit!" Mk. 16:16; Eph. 4:5; 5:18.
18. For ever subsequently, all members of the Church Visible have thus been baptized by the Spirit into one body. I Cor. 12:13. This means baptized by the Spirit at their water baptism. It does not mean some sort of post-baptismal 'second blessing' via a waterless Spirit-baptism! Thus Luther, Calvin, Beza, Kuyper, and Bruner. See here our separate article Spirit-ual Water-Baptism in First Corinthians 12:13. As to be expected, II Cor. 1:21-22 has the same teaching: "God is He Who keeps on establishing us (bebaioon heemas) together with you in Christ; and Who [at water-baptism!] anointed us (chrisas heemas) and also sealed us (sphragisamenos heemas), after having given (dous) the earnest [or ‘down-payment’] of the Spirit in our hearts!” Cf. Rom. 4:11; Col. 2:11-13; Rev. 7:4. As the great Australian theologian Dr. P.E. Hughes has said in his famous Commentary on Second Corinthians (1:21f): “In Rom. 4:11 [cf. 4:24f & 6:3-5] Paul describes as a seal [sphragida] the Old Testament sacrament of circumcision, of which the New Testament sacrament of baptism is the counterpart…. In the Early Church…it became customary to refer to baptism simply as 'the seal'….
For Paul, his baptism…was an experience of tremendous significance…. Baptism need not and indeed should not be excluded from the picture here…. Various commentators have wished to identify the anointing and the sealing of which Paul speaks in this passage either separately or conjointly with the rites of baptism…. A more satisfactory arrangement [is] to identify the anointing…with the single event of baptism" etc.