Baptism is really the burying of the old man as we symbolically die to the way we were, coming up out of the water as a symbolic resurrection of the new man.
Answer:
You are right in stating that it requires the application of the sacrificial blood of Jesus Christ to make the forgiveness of our sins possible. This is confirmed in Revelation 1:5: "From Jesus Christ, the faithful witness, the firstborn from the dead, and the ruler over the kings of the earth. To Him who loved us and washed us from our sins in His own blood" (emphasis added throughout).
Revelation 7:14 further speaks of "the ones who come out of the great tribulation, and washed their robes and made them white in the blood of the Lamb."
The New Testament abounds in scriptural passages affirming the majestic importance of Christ's sacrifice to cover our sins. Yet Ananias instructed Paul, after God had miraculously struck him down on the road to Damascus, "Arise and be baptized, and wash away your sins, calling on the name of the Lord" (Acts 22:16).
As you have written, and as Paul explains in Romans 6:2-6, water baptism symbolizes the death of the old sinful, selfish man. But in a figurative sense it also pictures the washing away of our sins.
Notice Hebrews 10:22: "Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water." These two washings, the blood and the water, work beautifully together. They are not in opposition. They are not mutually exclusive. They are inclusive and in harmony—perfectly complementing one another.
Ezekiel 36:25-27 also helps us to understand that cleansing with water can symbolize washing away sins. God says: "Then I will sprinkle clean water on you, and you shall be clean; I will cleanse you from all your filthiness and from all your idols. I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh. I will put My Spirit within you and cause you to walk in My statutes, and you will keep My judgments and do them."
Still, only Christ's perfect sacrifice provides the spiritual mechanism for God to forgive our sins upon repentance and faith (see Acts 20:21; Romans 3:25). Although water baptism does not of and by itself forgive our transgressions of God's law, it remains one of the required steps in the salvation process.
The apostle Peter firmly stated, "Repent, and let every one of you be baptized in the name of Jesus Christ for the remission [forgiveness] of sins; and you shall receive the gift of the Holy Spirit" (Acts 2:38). The second Gospel account clearly affirms, "He who believes and is baptized will be saved" (Mark 16:16).
In Ephesians 5:25-27 Paul wrote that "Christ also loved the church and gave Himself for her, that He might sanctify and cleanse her with the washing of water by the word... not having spot or wrinkle or any such thing, but that she should be holy and without blemish." God's Word itself plays its own role in keeping us spiritually clean.
Water cleanses and was therefore used figuratively and symbolically by Jesus Christ and His apostles to help illustrate the true conversion process. They taught spiritual principles by means of natural processes.
Several free booklets explain all this in further detail: The Road to Eternal Life , Transforming Your Life: The Process of Conversion and You Can Have Living Faith .
Baptism should also be understood as the means by which we publicly proclaim our acceptance of Jesus Christ as our savior.
I mean by this that your baptism is a rite or a ceremony by which you formally, officially, and before human witnesses accept and acknowledge Jesus Christ’s sacrificial death as the payment for the death penalty you have incurred for personally breaking God’s law.
The blood of Jesus sacrifice and the forgiveness of your personal sins will only apply to you if you are baptized... Christ’s blood only washes away our sins if we let it or want it.
So, in that sense the physical act of baptism does not itself wash away sin but is indeed a requirement for the forgiveness of sins to take place.