“Then Jesus traveled from the land of Galilee to the Jordan River where John was, so that John could immerse him, but John was trying to stop him. John said, ‘I need you to immerse me, yet you have come to me?’
“Jesus answered him, ‘Allow this for now, because this is the proper way for us to fulfill all righteousness.’ Then John did so.”
Jesus explained the purpose of his need to be baptized as “to fulfill all righteousness.” Our need is somewhat different, as we need to be baptized to demonstrate obedience (that notion of a response of a clear conscience that Brent has posted), and with the belief and knowing that in obedience to this token of Christ and his covenant, comes the remission of sins. Peter did after all state, “Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins.”
So, if we were working a math problem, the steps in this equation are that baptism, that is immersion in water, is for the express purpose of remission of sins. That means that if we too are baptized into Christ that we too will have then also fulfilled all righteousness as concerns us; and that we will have offered our response to the invitation; and that we will have completed the things that move in the direction of right as concerns us; in order that we can provide evidence of our request for cleansing before God. And that upon seeing our response, he will (as he has said) forgive our sins.
You can bury many things, but whatever you bury must be covered up. And chances are that if it was alive it is no longer when buried. Now, we don’t leave people under the water to stop their pulse, but they enter the water to symbolize that they are to become dead to sin. They then are to rise in newness of life – with hope in a new and different purpose and direction. They are redeemed by Christ.
Paul said, “Or do you not know that as many of us as were baptized into Christ Jesus were baptized into His death? Therefore we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life.
“For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin.
“For he who has died has been freed from sin. Now if we died with Christ, we believe that we shall also live with Him, knowing that Christ, having been raised from the dead, dies no more. Death no longer has dominion over Him. For the death that He died, He died to sin once for all; but the life that He lives, He lives to God.
“Likewise you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord.”
You give up being a slave to sin and become a slave to Christ. Yet it is a willing transposition and transaction, fostered out of our own free will. “For as many of you as were baptized into Christ have put on Christ. ” So, to end this exercise: you cannot put on Christ without immersion, and without immersion and therefore without Christ, there can be no remission of sins.
“So now, what are you waiting for? But get up and be immersed, and wash away your sins; calling on the name of the Lord.”
Every listed case for conversion in the NT had to comply with the command, all of which were adults, and so must all others of age and consenting. And which dear infant is it that can call upon the name of the Lord, or has considered sins they need to desperately dispose? And which of you washes clean dishes instead of the dirty ones? Be baptized, and be saved; that is if you will.