Galatians begins with a series of curses on those who teach a “different gospel.” Paul then relates a series of stories about his relationship with the other apostles to make the point that the true gospel teaches salvation by faith. He wraps up chapter 2 with some of the strongest statements on the sufficiency of faith to save found in the Bible.
(Gal 3:5-8 ESV) Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith – 6 just as Abraham “believed God, and it was counted to him as righteousness”? 7 Know then that it is those of faith who are the sons of Abraham. 8 And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.”
Amazingly, Paul calls “gospel” God crediting Abraham with righteousness because of his faith. His point is that the Gentiles are saved by faith because of God’s covenant with Abraham. It’s the same promise, and so both are “gospel.”
(Gal 3:9-12 ESV) So then, those who are of faith are blessed along with Abraham, the man of faith. 10 For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.” 11 Now it is evident that no one is justified before God by the law, for “The righteous shall live by faith.” 12 But the law is not of faith, rather “The one who does them shall live by them.”
The Law cannot save; therefore, not only are the Gentiles saved by faith, but so were the Jews. After all, “no one is justified before God by the law.” This is true not only while Paul is writing but has always been true.
(Gal 3:13-14 ESV) Christ redeemed us from the curse of the law by becoming a curse for us – for it is written, “Cursed is everyone who is hanged on a tree” – 14 so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
As much as I’d love to pause here as talk about the atonement and the Spirit, for now, the point is that Jesus died so that “the blessing of Abraham” (salvation by faith) “might come to the Gentiles.” The Jews did not yet have the Spirit (with rare exceptions), but they already had the promise of salvation by faith.
(Gal 3:17-18 ESV) This is what I mean: the law, which came 430 years afterward, does not annul a covenant previously ratified by God, so as to make the promise void. 18 For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.
The Law did not annul the promise of salvation by faith. Therefore, the Jews are saved by faith – and so are the Gentiles. God keeps his promises, and his promises to Abraham extended to his descendants.
(Gal 3:21-26 ESV) Is the law then contrary to the promises of God? Certainly not! For if a law had been given that could give life, then righteousness would indeed be by the law. 22 But the Scripture imprisoned everything under sin, so that the promise by faith in Jesus Christ might be given to those who believe. 23 Now before faith came, we were held captive under the law, imprisoned until the coming faith would be revealed. 24 So then, the law was our guardian until Christ came, in order that we might be justified by faith. 25 But now that faith has come, we are no longer under a guardian, 26 for in Christ Jesus you are all sons of God, through faith.
We’ll not take on the difficult question of why God gave the Law if it could not save. That’s for another day. For now, the point remains that “you are all [Jews and Gentiles] sons of God, through faith.” The promise given to Abraham now, through Jesus, has been extended to Gentiles.
(Gal 3:27-29 ESV) For as many of you as were baptized into Christ have put on Christ. 28 There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. 29 And if you are Christ’s, then you are Abraham’s offspring, heirs according to promise.
Suddenly, baptism appears – without explanation – but to make the point that somehow baptism explains (“for” means here “as explained by the fact that”). It all leads to the conclusion that everyone with faith – assumed to be the same people who’ve been baptized – “are Abraham’s offspring” and therefore “heirs according promise,” that is, we inherit the promise given to Abraham – salvation by faith.
Unlike in Rom 6, Paul isn’t using baptism to make a point about Christian ethics. Rather, he’s telling his readers that they know they are all “sons of God, through faith” because their baptism assures all of them of this fact. The English translations tend to end v. 26 with a period, but in the original Greek, v. 27 is part of the same sentence:
(Gal 3:25-27 ESV) But now that faith has come, we are no longer under a guardian, 26 for in Christ Jesus you are all sons of God, through faith[,] 27 for as many of you as were baptized into Christ have put on Christ.
“For” translates the Greek gar. In English, verses 26 and 27 both begin with “for” (gar). According to Thayer’s,
Moreover, not the number but the nature of the word after which [gar] stands is the point to be noticed …
It’s concealed in the English, but in the Greek, in both verses the gar follows “all.” Hence, Paul’s point is that all are saved as shown by the baptisms of both Jews and Greeks, slaves and free, male and female. He’s building a case for the universal availability of the gospel: unlike circumcision, it’s not just for free male Jews. Paul is not arguing Calvinist vs. sacramental baptism theology. Rather the fact the Jews and Gentiles, slaves and free, male and female are all baptized demonstrates that all are saved by faith in Jesus.
What explains or demonstrates that we are no longer subject to the Law as guardian? The fact that we are all sons of God though faith. What explains or demonstrates that we are all sons of God through faith? That those who have been baptized are the same people who put on Christ. In other words, our baptisms demonstrate the truth of the fact that we’re all saved by faith. Even the Jews had to be baptized to enter Jesus.
Probably Paul mentions baptism here because he is about to emphasize the oneness of those who are in Christ (v. 28, where the “all” of v. 26 recurs): the visible sign of this oneness is not faith but baptism; the oneness with Christ that is symbolized in baptism is the basis for the oneness in Christ (cf. Eph 4:5, “one Lord, one faith, one baptism”). Here, as in Rom 6, “there is an appeal in the presence of those who were in danger of forgetting spiritual facts, to the external sign which no one could forget.”
Ronald Y. K. Fung, The Epistle to the Galatians, The New International Commentary on the New Testament. (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1988).
Baptism in the New Testament invariably implies a radical personal commitment involving a decisive no to one’s former way of life and an equally emphatic yes to Jesus Christ. Historically, however, the doctrine of believers’ baptism has also implied a gathered church, a community of intentional disciples marked off from the world by their commitment to Christ and to one another. Baptism is the liturgical enactment of the priesthood of all believers, not the priesthood of “the believer,” a lonely, isolated seeker of truth, but rather of a band of faithful believers united in a common confession as a local, visible congregatio sanctorum (“gathering of saints”). Paul’s discussion of baptism in Galatians comes at a critical juncture in his quest to redefine the people of God, the family of faith, the true children of Abraham. For him baptism was an outward sign not only of the personal response of faith but also of the new community that belongs to Christ by virtue of grace alone. …
Baptism is recalled as the concrete moment in their own life in which they for their part confirmed, recognized, and accepted their investing with Christ from above, their ontic relationship to him, not only in gratitude and hope but also in readiness and vigilance.
Timothy George, Galatians, The New American Commentary. (Nashville: Broadman & Holman Publishers, 1994), 30.
That is, baptism demonstrates the unity of the Jews and Gentiles because it incorporates the convert into a united church. In fact, because baptism is always administered by someone else, it’s an action of the church that accepts the convert’s confession of faith and initiates him into the community of the saved.
Baptism in the NT is always in the passive voice. It’s not something done but a gift received.
 Non-Jewish male slaves could be circumcised and so participate in Passover (Exo 12:44). Circumcision for male Jews, however, was mandatory.
 This is not to say that baptism fails if administered by a lost person or outside the faith community. Rather, the intended, normative (intended to be normal but not necessarily universal) case is baptism within a congregation of faith. The convert confesses Jesus as Lord (Rom 10:9), and the church accepts him into the community of the saved by baptism.
This statement should not be confused with the Southern Baptism practice of voting whether someone may join a congregation. Baptism is “into Christ” not into a local congregation. But being baptized into Christ is also being baptized into his body, the church-universal. And baptism is received, not done for oneself, and when possible, it’s received from God by the hands of the church-universal.
Again, this is not the Catholic sacramental theology that the church as institution (the bishops, cardinals, pope, etc.) determines who may be saved. “The church” means the body of believers, not the institutional leadership.
In Church of Christ practice, occasionally the leadership of the local congregation will delay a requested baptism because the person requesting baptism is considered too young to fully understand the nature of the commitment that baptism involves or because the person requesting baptism doesn’t have sufficient understanding to be baptized – yet.
The same thing happens when any Christian studies the Bible with a non-Christian. Often the non-Christian requests baptism before she’s been taught enough about Jesus to follow him as Lord. The Christian teacher quite properly delays baptism until the student is ready.
Finally, I’m not saying that someone must be baptized during the assembly. The church-universal is the body of believers, whether or not assembled. The “community of the saved” is the body of believers associated in active fellowship, which includes but isn’t limited to the assembly.
In my congregation, if someone requests baptism on a Tuesday night, they’ll probably be baptized on that Tuesday night. But text messages and Facebook posts will go out inviting other Christians to be there to welcome the new brother or sister into the fellowship of believers. It’s unthinkable that someone might be baptized without Christian brothers or sisters there to hug, pray, applaud, and sing in celebration of the conversion. We think it’s a big deal, don’t mind being spontaneous, and celebrate without reservation.