Commenting on Paul’s use of preformed Christian tradition and the salvific efficacy of water baptism therein, in 1 Cor 6:11 (as well as Rom 6:3), Jerry L. Sumney (professor of biblical studies at Lexington Theological Seminary) wrote:
Romans 6:3 and 1 Cor 6:11 may cite traditions that relate the death of Jesus to baptism. Paul even introduces the Rom 6 citation with what some see as a recitative hoti. The preceding phrase, “don’t you know,” may also indicate that Paul is about to cite a known formula. The use of apoloyō (“wash”) in 1 Cor 6:11 is a hapax legomenon in Paul, and it appears only one other time in the New Testament (Acts 22:16), where it also refers to baptism. Its use in the passive suggests to many interpreters that it is already technical language for baptism. Since Paul does not use this metaphor to describe the effects of baptism elsewhere, it seems likely that he is not the originator of this interpretation. Raymond Collins notes that in addition to the singular o “washed” the phrase “our Lord Jesus Christ” is another traditional phrase . . . The verb hagiazō (“to make holy”) is also relatively rare in Paul. As often as he uses the cognate nouns “saints” to describe believers (at least twenty-three times), he uses the verb only ix times. It is related directly to baptism only in 1 Cor 6:11. So this is an unusual sense for Paul, especially when compared to its two uses in 1 Cor 7:14, where an unbeliever is made holy through association with a believing spouse. There is then significant, but not decisive evidence that Paul is citing or alluding to preformed tradition in Rom 6:3 and 1 Cor 6:11. If he is citing traditional material in either passage, it indicates a pre-Pauline (or at least non-Pauline) view of baptism understood as a rite that is incorporated the baptized into the death of Christ. Furthermore, this interpretation of baptism assumes that Jesus’s death is “for us” and has salvific effect. . . . [on 1 Cor 6:11] Interpreters often find Paul drawing on the language of a baptismal tradition here. Fragments of the tradition are fairly obvious, especially the claim that these were done “in the name of . . .” . . . The relationship between baptism and a cleansing from sin is made in Eph 5:26; Titus 3:5; Heb 10:22. These multiple citations of this understanding suggest that it was earlier than and beyond Paul’s influence. In addition, the verb apelusasthe (“to be washed”) appears only here in the Pauline corpus, indicating that Paul draws it from a source beyond his usage. Further, that this verb appears in the passive may also indicate that it is part of the tradition.
If the substance of Paul’s assertions about baptism here is drawn from earlier tradition, as seems probable, then baptism’s association with forgiveness of sins, with granting holiness, and perhaps with the coming of the Spirit are all part of the church’s message before Paul wielded significant influence. The Didache’s use of baptism as the line of demarcation between those who may participate in the Eucharist and the “unholy dogs” also indicates that it sees baptism as the rite that cleanses and makes one holy (9.5). Even if we determine that the terminology of cleansing and making holy as they appear in 1 Cor 6;11 is not directly taken from earlier tradition, this passage in the Didache indicates that these understandings are part of the church’s teaching before the time of Paul and outside his influence. (Jerry L. Sumney, Steward of God’s Mysteries: Paul and Early Church Tradition [Grand Rapids, Mich.: Eerdmans, 2017], 35-36, 81-82, emphasis added, comment in square bracket added for clarification)
Elsewhere, on Gal 3:27-28 and 1 Cor 12:13, Sumney writes:
Gal 3:27-28 and 1 Cor 12:13 [are] citations of a preformed baptismal liturgy. The evidence includes its pairs of opposites, the insertion of baptism into the context, and the change from first person plural (“we”) to second person plural (“you”). These all indicate that (at least) Gal 3:27-28 is a set piece that Paul inserts into his argument. This formula provides evidence for an early partially realized eschatology. In this formula, those baptized are brought “into Christ” and have “been clothed with Christ.” This identification with Christ beings the baptized into the realm that is determined by Christ’s identity. The eschatological nature of this claim is evident in the return to oneness. This is nowhere more clear than in the allusion to Gen 1:27. The obvious change in the pattern of the opposed pairs in the formula shows that the oneness that the liturgy proclaims is a return to the primordial or Edenic ideal state. It is a common feature of apocalyptic Judaism to see the coming age as a return to the ideal original state of creation. This formula draws on that understanding in its allusion to Gen 1:27. The formula also proclaims that this state of existence is a present reality for the baptized. (Ibid., 99, emphasis added, comment in square bracket added for clarification)
Therefore, the only conclusion one can reach, based on the evidence, is that both Paul and the earliest strata of pre-Pauline Christian tradition explicated transformative justification as well as baptismal regeneration.
