In Eph. 4:3-6, we are told to be diligent in preserving the unity of the Spirit in the bond of peace. V. 4 says there is one body (universal), one Spirit (Holy Spirit). V. 5 says one Lord (Jesus Christ), one faith (the belief that saves) (“That we all hold in common” Jude 3) and one baptism. It is this “one baptism” that puts a believer “in Christ” - the Holy Spirit is the one that baptizes believers into the “one body” (1 Cor. 12:13).

 Eph. 4 is all about unity, God’s work is to unite us to Himself and to each other. All of the above-mentioned are spiritual workings and functions of Christ and the work of the Holy Spirit. Only one of the two types of baptism is essential to Christianity. Baptismal regenerationists want us to believe that of the “seven unities” mentioned in Eph. 4:3-6 this is the only one that is physical and ceremonial in nature, rather than spiritual. Paul is speaking of the “unity of the Spirit,” therefore the baptism spoken of above should be interpreted as a Spirit baptism rather than a water baptism, since the context of the passage is dealing with the Spirit’s work. It is listed side by side with one Lord and one faith. Notice v.7, “But to each one of us grace was given according to the measure of Christ's gift.” That gift is the Holy Spirit.

There is only one baptism, only one immersion that puts one in the body of Christ. If you are not baptized in the Holy Spirit then you are not in Christ. Rom. 8:9 states: “if any man has not the Spirit of Christ, he is none of his.” (Jn. 3:24 and 4:13 say the Holy Spirit abides in us). 1 Cor. 6:19-20, the Holy Spirit's indwelling makes the body of the believer his temple (Eph. 2:21-22).

This means you are not a Christian, you are not His possession without the Spirit. You can be baptized by water but still not have the Spirit. It is Spirit baptism that buries us with Christ into his death (Rom. 6:3-7). The one baptism mentioned cannot be water but the invisible work of Spirit baptism is visibly represented through water baptism. There is one God, there is one [Spirit] baptism, not two or more.