Baptism and the Blood
The blood of Jesus saves us from our sins: the blood was "shed for many for the remission of sins" (Matthew 26:28). What does baptism have to do with the blood?
Peter preached, "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost" (Acts 2:38). Note that the expression "for remission of sins" is the same as in Matthew 26:28. Jesus shed His blood for the remission of sins. How can both be true?
The answer is in Romans 6:3-4: "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life." This tells us that when we are baptized into Christ we are baptized into His death. We contact Christ's blood when we obey the gospel and are baptized into Christ.
What saves us? The blood of Jesus. How do we avail ourselves of the blood? Through baptism into Christ. Is baptism a work of our own merit? No. We simply must submit to the will of God. Now, how can anyone deny the necessity of baptism?