Galatians: Depth Gospel

Sources: I. Howard Marshall et al., Exploring the New Testament: A Guide to the Letters and Revelation (IVP, 2002); Raymond E. Brown, The New Testament: an Introduction (Doubleday, 1997); Bart Ehrman, The New Testament: A Historical Introduction to the Early Christian Writings, 3d ed. (Oxford, 2004).

I. Galatians' Occasion and Legacies
An early letter, possibly Paul's first (and thus the earliest Christian writing).

Also possibly predating the Jerusalem meeting in Acts 15.

Paul's churches in Galatia face teachers of unknown origin (5:10):

Christian teachers (from Jerusalem? from James? 2:12) are commanding Torah obedience, signified by circumcision (1:6-9, 2:6-2:21, 6:12-13; cf. Gen. 17:9-14).
For the formerly pagan Galatians (4:8), this would amount to telling 'a different gospel' (1:6) than the good news of the grace of the Messiah (1:1).
Paul skips the standard thanksgiving and hotly rebukes them.

Paul must overturn their claim that Torah observance is mandated by God to the faithful.
Paul crafts a brilliant, dense rabbinical argument to turn the tables on his opponents, diagnose the heart of their issue, and restore the integrity of the Galatians' trust in Christ.
The letter, with Acts, reveals a divide in the church's youth that was healed through discernment, conviction, listening, compromise, and tolerance.

Read somewhat out of context, it drives the European Reformations and grounds Protestant Christianity.
The phrase "faith of Christ" (pistis christou) is pulled into that orbit, and has recently been newly controversial.

II. The Marks of Jesus: The Gospel in Galatians
Paul gets to the bottom of the presenting issue:

Gentile believers want to keep the Torah (4:21, 5:2).	Correct them! (But how?)
Unauthorized teachers are trying to ‘Judaize’ them (3:1, 2:7).	Assert the divine source and authority and apostolic recognition of Paul’s gospel and apostleship (1:11-12, 1:15-16a, 1:6-9, 1:16b-2:3, 4:14) alongside Peter’s (and James’) gospel to the circumcised (2:7-8) and versus false brethren bearing other (non-)gospels (2:4-6, 5:7-10).
They believe the Torah is still binding on all God’s people (2:15-16).	Justification comes by Christ-faith, not Torah obedience (2:15-16, 5:3-4).
	Belonging to Christ ends the old life’s ties, including Torah ‘captivity’ (2:18-20, 3:22-23), and slavery to powers (4:3-10), and ushers in new life in the Spirit (3:1-5).
	The Torah (Pentateuch) centers on God’s promises beginning with Abraham (in faith) and transcends Moses’ covenantal rules (3:10-19, 4:22-28).
False brethren are after others’ approval, to satisfy their intuitions (1:10-11, 2:11-14, 4:17, 6:12) ...	Paul’s ministry, formerly like theirs (1:13-14), is no longer undertaken for others’ approval (1:1, 1:10, 2:6). Self-promotion is self-deception (6:3-5).
	Point out their teaching has unsettled them, made them newly suspicious of Paul (and thus Christ), and undermined their blessedness (4:11-20). Warn them of its spreading, destructive effects (5:9, 5:13).
… out of offense to the cross (5:11, 6:12-15).	Being circumcised reverses Christ’s work, abandons him, his grace, and his inheritance (3:3, 3:23-4:9, 5:4), and returns to slavery (5:1).
Resistance manifests the flesh’s futile rebellion against the Spirit (5:17-24).	Belonging to Christ crucifies our self-assertive, desirous flesh (5:24). Christ’s Spirit brings freedom and sonship/heirdom (3:14, 4:26, 5:1, 5:13, 5:5-6) and fruit/virtue suited to that life together anticipating new creation (5:22-24).
The way out is Christ’s new creation (1:1b, 6:15-16).	Paul prescribes walking with the Spirit and refusing the flesh (5:16, 5:25), gentle restoration and burden-bearing (6:1-2, 6:8-10).

Paul attends to every level of the challenge, from the surface to its deepest depth.