No man can work his way to God, for, “No one does good, not even one,” and no one can will his way to God, for, “No one understands, no one seeks for God.” It is for this reason that the apostle writes later in the Epistle to the Romans, “So then, [salvation] depends not on human will or exertion, but on God who has mercy” (v. 9:16), and why he quotes the prophet Isaiah later in that same chapter concerning Israel, “If the Lord of hosts had not left us offspring, we would have been like Sodom, and become like Gomorrah” (v. 9:29).
The Good News is that God has not left us to ourselves. For Paul declares in Romans 5 that that same Offspring that preserved the life and the holiness of ancient Israel has come into the world as the Second Adam–the second head of the human race–and where the first Adam failed, the Second Adam, Jesus Christ, succeeded. Where the first Adam brought judgment into the world, the Second Adam–Jesus Christ brought justification into the world. Where the first Adam brought the reign of death, the Second Adam–Jesus Christ brought the reign of righteousness unto eternal life. Where the first Adam was disobedient, the Second Adam–Jesus Christ was obedient. Where the first Adam brought the condemnation of the law, the Second Adam–Jesus Christ brought the abundance of grace.
Therefore, the question becomes not, “What work must I do, or how shall I exercise my will,” but, “How am I, a son of Adam, to be taken out from Adam’s headship and placed under the headship of Jesus Christ?” “How am I, a disobedient and faithless person, to be placed under the One who fulfilled the obedience of faith?”
And thus we come to the third option of dealing with Paul’s “obedience of faith,” and that option is baptism. “What business does water have to do with obedience?” you might ask. The apostle Paul gives perhaps the most thorough explanation of this truth in Romans 6-8:17, however, before we look at that text, it would be profitable to look at Scripture outside of the apostle Paul. Concerning this truth, the apostle Peter writes:
For Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit, in which he went and proclaimed to the spirits in prison, because they formerly did not obey, when God’s patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water. Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ, who has gone into heaven and is at the right hand of God, with angels, authorities, and powers having been subjected to him (1Pt. 3:18-22).
The apostle intimates that baptism in its essence is not the removal of dirt from the body, i.e. by water, but it is an appeal to God for good conscience. How does one have a good conscience? By doing as he ought to do–by obeying the commands of God. We know this is the case, for in the paragraph preceding this text, the apostle writes, “Now who is there to harm you if you are zealous for what is good? But even if you should suffer for righteousness’ sake, you will be blessed … having a good conscience, so that, when you are slandered, those who revile your good behavior in Christ may be put to shame” (1Pt. 3:13, 14, 16). Therefore, baptism by God results in a good conscience which comes about by obedience.
And lest we think that baptism is a post-Christ ordinance, the prophet Ezekiel testifies about this reality and its significance in the New Covenant:
I will take you from the nations (or Gentiles, cf. Is. 60) and gather you from all the countries and bring you into your own land. I will sprinkle clean water on you, and you shall be clean from all your uncleannesses, and from all your idols I will cleanse you. And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in my statutes and be careful to obey my rules. You shall dwell in the land that I gave to your fathers, and you shall be my people, and I will be your God (Ez. 36:24-28).
Therefore, the prophet declares, as the apostle declares, that baptism results in the obedience of God’s people. How? Because God places in his people a new heart and a new spirit, and he puts his Spirit in us so that we will “walk in [his] statutes and be careful to obey [his] rules.” Therefore, man’s inability to fulfill the obedience of faith is remedied by God’s ability, for it is God who works in his people to bring them to obedience through Jesus Christ. The question that remains then is, “How is this accomplished?”