In his discussion of Romans 6:1-10 on the topic of baptism, James Dunn again reads into the text unwarranted assumptions. For example, he writes,
Paul is dealing with the spiritual reality of death to sin (and life to God) and in vv. 3–6 he depicts this theme under a series of different images. The first metaphor we are already familiar with – vbapti,zein eivj Cristo.n VIhsou/n. It is drawn from baptism, but does not itself describe baptism, or contain within itself the thought of the water-rite, any more than did the synonymous metaphors of putting on Christ (Gal. 3.27) and being drenched with the Spirit (I Cor. 12.13). The first and only concrete reference to water-baptism in Rom. 6 is the phrase dia. tou/ bapti,smatoj; this phrase marks an extension of Paul’s thought to embrace the water-rite, and indicates the relation between the metaphors (of baptism and burial) and the rite itself in the actual event of conversion-initiation, as we shall see. But when is used in its metaphorical sense any element which is involved is the Spirit, and what it describes is the spiritual mystical reality of union with Christ effected by God. Union with Christ means union with his death. Of the completeness of this death the rite of baptism is an excellent symbol: the disappearance, however brief, below the surface of the water represents a burial rather well – and in this case, participation in the completeness and finality of Christ’s death…. In short, each metaphor points directly to the spiritual reality and not to baptism, which is itself a metaphor. [Dunn, J. D. G. (2011-08-22). Baptism in the Holy Spirit (Kindle Locations 3105ff). Kindle Edition.]
Notice, however, that he assumes that Spirit baptism and water baptism are mutually exclusive. There is nothing in the context which would indicate that the text is not talking about water baptism, unless we read the text with the prejudice that water baptism has nothing to do with union with Christ. But reading the text this way is eisegesis, importing our preconceived notions into the text.
Douglas Moo is much more in line with the actual text when he comments,
Paul’s reference is to the Roman Christians’ water baptism as their outward initiation into Christian existence. To be sure, a few scholars have denied any reference to water baptism here….But, without discounting the possibility of allusions to one or more of these ideas, a reference to water baptism is primary. By the date of Romans, ‘baptize’ had become almost a technical expression for the rite of Christian initiation in water, and this is surely the meaning the Roman Christians would have given the word (Romans, 359).
Thomas Schreiner is correct, then, to say,
We are asking the wrong question, therefore, if we ask whether Spirit or water baptism is in view in Rom 6:3-4. Other Pauline texts suggest that water baptism and reception of the Spirit occurred at conversion. In my judgment Paul would have been initially puzzled if we asked him, ‘Do you mean Spirit or water baptism in these verses?’ He would reply, when he understood the question, ‘Both’ (“Baptism in the Epistles” 74).