Which is the one baptism referenced in Eph 4:5? Is it of water or of identification into Christ's death and resurrection making us part of the Body of Christ?
It is the "water" baptism which identifies us with the death, burial, and resurrection of Christ, for our old man, the Adam; to wear as a sign of our being in His Name, by faith, and shows our faith that the old man body of death will also rise from the dust in His image.
.It is water baptism which is the casting away, the remitting, of our sins by sending them away from us, with Jesus', to hell, represented as the "Deep".
Eph 4:5 says there is "one Lord"; but the Father is Lord and the Holy Spirit is Lord, and claiming only that Jesus is the one Lord, as they deny the water is the one baptism of the faith, the MAD doctrine then teaches hear-say by denying the Holy Spirit baptism of regeneration of Spirit [second birth, born again from above], and the Holy Spirit baptism of the Glory/Fire, which is the measure of that which is to come, sent by Jesus from the Father when He received it without measure, on Pentecost, as the Temple of God not made with hands, seated above, as Firstborn of earth;
and denies the Holy Spirit baptism of Enduement with power from on High, sent to regenerated in Spirit adopted sons of God to serve Him, in His name with.
The MAD doctrine followers make the claim of one Lord to the exclusion of the Father and the Holy Spirit, just as they make the claim of one Baptism to the exclusion of the claim that the Father is not Lord, that the Holy Spirit is not Lord, and that the Son only is Lord.
By this reasoning they deny the Trinity in the work of salvation for every person who calls on the Name of the LORD -come in flesh,
The Father is LORD, and He is not come in human being flesh.
the Holy Spirit is LORD, and He is not come in human being flesh.
The Son is LORD, and He is come in human being flesh, and the Church is built on His New Man body as the Last Temple for the Father's glory to indwell in His Glory.
It is His Church, which He will present to the Father for the Glory to indwell in the regeneration.
It is Faith in His Name which causes us to be joined to His Church, and it is water Baptism in His name which is the One baptism for the One Church which is the One Faith of the One LORD's Name.