Ananias said to Paul "What are you waiting for, arise, be baptized and wash away your sins, calling on the name of the Lord." Only Christ blood washes away sin, and baptism puts us in Christ's death where He shed His blood (Romans 6:3), BINGO! We have a winner!
As in Colossians 1:14, "through His blood" is a reference not limited to the fluid as if the blood has saving properties in it's chemistry and we contact it in the waters of baptism, but is an expression pointing to the totality of Christ's atoning work as a sacrifice for sin. The word "cross" is also used similarly to refer to the whole atoning work of Christ on the cross (1 Corinthians 1:18; Galatians 6:12,14; Ephesians 2:16).
Yes, He uses our "immersion" into Christ's death to kill the old man...entirely, and be raised with Christ to walk in newness of life.
If baptism is taken as the instrumental cause, then Paul contradicts what he had established before, namely that justification is by FAITH, not baptism. *Hermeneutics. Paul clearly teaches that what is signified in baptism (buried and raised with Christ) actually occurs "through faith." Christians are "buried with Him in baptism, in which you also were raised with Him through faith in the working of God, who raised Him from the dead" (Colossians 2:12). Justification on account of union in Christ's death, burial and resurrection is brought about “through faith” - and is properly symbolized by dipping the new believer in and out of the water.