“Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.” -Romans 6:3–4
Here is a passage that explains in full what Paul merely hinted at in the previous verses (1-2). Baptism is not merely memorial as some would imply by calling it an ordinance. Baptism is sacramental in that it is the appointed sign which signifies the death of our old man, the one born under the headship of the first Adam. While baptism does not wash away sins per se, it is that unique and genuine symbol of our union with Christ in his death and resurrection by the Holy Spirit.
“For in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit.” -1 Corinthians 12:13
This union of ours with Christ into his death further brings forth fruit by way of his resurrection. Like Christ, we are raised from the dead by the glory of the Father, that we might walk in newness of life. This spiritual condition of this new life in Christ is real even now while we wait for the death of our bodies, that we might be resurrected in our new bodies at the appointed day. Cf Paul’s two letters to the Corinthians:
“For this perishable body must put on the imperishable, and this mortal body must put on immortality. When the perishable puts on the imperishable, and the mortal puts on immortality, then shall come to pass the saying that is written: “Death is swallowed up in victory.” “O death, where is your victory? O death, where is your sting?” The sting of death is sin, and the power of sin is the law. But thanks be to God, who gives us the victory through our Lord Jesus Christ. Therefore, my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord your labor is not in vain.” -1 Corinthians 15:53–58
“For in this tent we groan, longing to put on our heavenly dwelling, if indeed by putting it on we may not be found naked. For while we are still in this tent, we groan, being burdened—not that we would be unclothed, but that we would be further clothed, so that what is mortal may be swallowed up by life.” -2 Corinthians 5:2–4