The ancient church fathers without exception regarded baptism as the consummating act; and therefore they called it teliosis, the consummation. It is not important what they thought, they were not inspired; what do the scriptures teach?? In their writings they did understand washing of regeneration and the regeneration as synonymous with baptism.
We need to now ask the import of the phrase washing or bath of regeneration, either as commonly used or as explained by the Apostles. It is our understanding that the phrase is a definition of water baptism. Paul was a Hebrew and the Holy Spirit used a style for each writer as was common to him, therefore, we must understand the Hebrew style. The water of baptism, or the water in which we are regenerated, represents a process. Loutron, the word which more properly signifies the vessel that contains the water, than the water itself, is rendered bath. In this manner it describes the vessel containing the fluid or the use made of the bath. What more natural for the Jew accustomed to speaking of “the water of separation,” to speak of “the bath of regeneration”? If the phrase “water of purification” meant water used for the purpose of purifying a person—if “the water of separation” (Numbers 19:7,9,13,20,and 21—see also Numbers 31:23) meant water used for separating a person from the penalty imposed because of his sin—what more natural that the “bath of regeneration” should mean water used for regenerating, bringing him back into the fellowship with God???
The New Testament confirms this explanation. We find the word loutron once more used by the same Apostle, in the same connection. In his letter to the Ephesians, Paul affirms that Jesus has sanctified-separated, purified His Bride from sin- with the water of purification, a loutron –bath—of water—because of the direction of the Word, the Holy Spirit.” Ephesians 5:26 This gets still more decisive. The King James, fully aware that the sense of this passage agrees with Titus 3:5, have, in both places, used the word washing or bath of water for the word loutron. What is called the “washing or bath of regeneration” (Titus 3:5) is in the other called the “washing or bath of water” (Ephesians 5:26)!! What is called saved in one is called cleansed in the other; and what is called the renewal of the Holy Spirit in the one is called the “Word” in the other; because the Holy Spirit consecrates or cleanses the Church through the Truth, as Jesus declared– prophesied it would in the Garden while speaking to the Father — “Thy Word is the Truth.” John 17:17 Or as He said in another place, ”Ye are clean through the Word that I have spoken to you.” John 15:3, also for usage see Acts 18:6; Revelations 19:8, 14 Man, who repents, is made clean, purified, forgiven as he obeys the direction of the Word—he is commanded to be baptized for the remission of sins—by the direction of the Word—the Holy Spirit— as the Spirit gave that Truth by the Apostles of Christ!! Paul, to the Hebrew Christians, says: “Having your hearts sprinkled from an evil-guilty conscience, and your bodies washed with pure water—or water that purifies or cleanses, you.” Hebrews 10:22 Peter declares: “baptism is the answer of good conscience—it is the means-way-process by which your sins no longer separate you from God—BECAUSE– the Holy Spirit directed the Apostles to preach baptism as that means-way-process by which sinners are saved. 1 Peter 3:21 No one, then would think, who is acquainted with Peter’s style, that while Paul represents persons as saved, cleansed, or sanctified by water; Peter unequivocally asserts that “we are saved” through water, or through baptism, as was Noah and his family—or as we would say it, today—the anti-type, immersion, does also “now save us”!!