This text cannot mean “separate but equal” and still end up with “one in Christ.” Forgive the Greek, but the balance of the text is rhetorically beautiful and the parallelism important.
οὐκ ἔνι Ἰουδαῖος οὐδὲ Ἕλλην,
οὐκ ἔνι δοῦλος οὐδὲ ἐλεύθερος,
οὐκ ἔνι ἄρσεν καὶ θῆλυ
neither Jew nor Greek,
neither slave nor free,
neither male and female (Gal. 3:28)
The logic is as beautiful as the rhetoric. Just previously, in v. 26, the apostle states that all believers in Jesus are now “sons of God” though their trust in Jesus. Given where Paul is going with this text, that would mean that Jew, Greek, slave, free, male, and female should all consider themselves “sons.” They are now all the “sons” of God. Of course, there is a lot of reasons why Paul would uses the masculine plural collective noun for God’s people. First, the ancient people of Israel were known in Scripture as the “sons” of Israel. Secondly, Paul has already played with the notion of adoption and that word is rooted in the notion of being made a son (cf. Rom 8:15, 23; 9:4; Gal 4:5; Eph 1:5). Thirdly, Paul is also working the Old Testament notion that the first born son was to received the largest portion of the inheritance. And Paul is certainly of the mind that Jesus is this “firstborn” Son of God. So when it comes to being a “son,” there is a lot to work with. And he wants all of us to be “sons.”
Now this in important: Those who have been baptized into Christ, have put on Christ—irrespective of other identity-markers to be named in the v. 28. Every believer is to be counted as if they were the Son. They have identified with Jesus, the Son and as such now stand in line to receive the full inheritance of the Son. The interpretation of the text become ludicrous if we begin to qualify—really we all know, this passage really only deals with salvation and not real life (wink, wink). You know, really Greek believers are second-class citizens in the kingdom of God and slaves can’t lead free people in the church because, well, they are slaves. If Paul is not radically “re-assigning” the typical and expected place of all of these categories, then the text doesn’t really make sense.
Significantly, if you think about it, the addition of “male and female” is unnecessary to Paul’s overall argument. The Jew-Greek distinction is at the heart of Paul’s ministry to include non-Jews. The slave-free split fits Paul’s discussion of “freedom” in Galatians. So why throw in male and female? Because, I think, Paul wants to show how radical the new creation really is (see Gal. 6:15).
Paul intentionally chooses words of gender-identity. Here we don’t have the normal word for man and woman (which can also be translated respectively husband and wife in some contexts). We have here a clear echo of Gen 1:27: So God created humankind in his image, in the image of God he created them; male and female he created them (ἄρσεν καὶ θῆλυ ἐποίησεν αὐτούς in the Greek translation of the OT; cf. Gen 1:27; 5:2; 6:19–20; 7:2–3, 9, 16). Paul goes from “nor,” “nor,” to “and.” “Nor” would have worked one more time but “male and female” preserves the echo of Gen. 1:27. Thus, the level of “no difference” between Jews and Greeks, between slave and free, has also to be between “male” and “female.”
Finally, the punchline of this text is “And if you belong to Christ, then you are Abraham’s offspring, heirs according to the promise” (Gal. 3:29). The point is clear. All of us, whether Jew or Greek, Slave or Free, Male or Female—if we are in Christ—are full heirs to God’s promise.
And that is Good News!