Those who want to take water baptism as a sacrament (a line on a checklist that one must fulfill as a precondition to salvation) will equivocate between the baptism of water, and the baptism of the Holy Spirit. A baptism in water symbolizes the Living Water (John 4:14) of the regeneration of the Holy Spirit. So when a person is “born again,” that is not a matter of water baptism, as some will allege, but rather, it is to literally be made anew by the power of God (2nd Corinthians 5:17). Since there are multiple things that a person can be baptized into, some will equivocate between the kinds of baptism. One can be baptized in oil, or in water, or in the Holy Spirit. So then, does Romans 6:3-5 refer to water baptism? I think that would be to use the word baptism equivocally. 
I might indicate first that in Paul’s masterpiece, the book of Romans, he ardently argues for salvation by faith alone to the exclusion of works. God is the just and the justifier of he who has faith in Jesus (3:26). But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness (4:5). He refers to salvation as a free gift (Romans 5:15). Since faith is credited as righteousness, and assuming that faith happens before baptism, it follows that salvation comes to the exclusion of baptism. I scarcely consider the idea that Paul contradicted himself one chapter later.
First a moment to read through the text. Romans 6:3-5: “Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death? Therefore we have been buried with Him through baptism into death, so that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life. For if we have become united with Him in the likeness of His death, certainly we shall also be in the likeness of His resurrection…”
The baptism of the Holy Spirit initiates a person into the body of Christ, In my article, Is Baptism Necessary For Salvation? I pointed out that the baptism of the Holy Spirit is what initiates a person into the body of Christ. Paul writes in First Corinthians 12:13, “We were all baptized by one spirit, into one body… we were all made to drink of one Spirit.” Thus the baptism that initiates a person in the body of Christ is the baptism of the Holy Spirit. If that is the case, it follows that when Paul refers to baptism in a salvific sense, he must be referring to the baptism of the Holy Spirit.
Now the one who believes that baptism is a necessary precondition to salvation might recoil that baptism of the Holy Spirit is simultaneous with water baptism. While that may be true in some cases, the overwhelming historical record in the book of Acts indicates time and again that the two baptisms come at different times (Acts 10:47). If the model is that they come at different times, then water baptism is excluded for regeneration. Does Romans 6:3-5 refer to water baptism? It cannot be. Salvation must come to the exclusion of water baptism.
Thus, when we read Romans 6:3-5, we ought to have it in our forefront that water baptism does not initiate a person into the body of Christ. Since the baptism in this passage is highly salvific, it cannot be referring to baptism in water.
The interpretation of water baptism does not align with what Paul is saying. Paul begins this chapter by asking, “what shall we say then? Are we to continue in sin so that grace may increase? May it never be! How shall we who died to sin still live in it?” He goes on to contrast a life of sin with baptism. We have been baptized i to Christ Jesus and into his death, for the glory of the Father, and now we walk in the newness of life (v. 4-5). We are no longer slaves to sin. We have been set free from sin. We are made new creatures by the power of God and the regenerating work of the Holy Spirit. That is the baptism to which Paul is referring. That is precisely the baptism of the Holy Spirit.
If it were referring to water, then it follows that one could have undergone the baptism in Romans 6:3-5 without first receiving the baptism of the Holy Spirit. A person may be water baptized and not yet receive the baptism of the Holy Spirit. Since the Holy Spirit is necessary for salvation (John 3:5), then the water in Romans 6:3-5 has the capacity to be a baptism for unbelievers! A person is baptized into Christ Jesus, into his death, walks in the newness of life, but does not have the indwelling of the Holy Spirit? But that is precisely what this view entails, because there are multiple occurrences in Acts in which the baptism of the Holy Spirit comes at a different time than water baptism.
Further, a person who does not have the Holy Spirit is incapable of walking in the newness of life. First Corinthians 2:14 reads, “the natural man does not accept the things of the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually appraised.” Does Romans 6:3-5 refer to water baptism? Since those in Romans 6:3-5 are leaving their life of sin behind, walking in the newness of life, united with Christ, dead to sin, it follows necessarily that these people must have been born again by the power of the Holy Spirit.
There is no water in Romans 6:3-5. There is Living Water. In John 7:38, the Lord said, “He who believes in Me, as the Scripture said, ‘From his innermost being will flow rivers of living water.'”
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