Galatians 3:29
Galatians 3:2929And if you belong to Christ, then you are Abraham’s seed and heirs according to the promise.
is awkward for the Watchtower's two-class soteriology because it says flatly: "if you belong to Christ, you are Abraham's offspring, heirs according to promise." Watchtower theology restricts the heavenly hope — and the new covenant, and the emblems at the Memorial, and being "Abraham's seed" in the full sense — to the 144,000. The other sheep are taught they are "friends of God" like Abraham rather than heirs with Christ. So 3:29 is typically either skimmed past, or the "you" is restricted retroactively to the anointed.
Paul's conclusion is universal by grammar and by context. Chapter 3 has argued that Gentiles, slaves, women, and Jews all have equal access to the Abrahamic inheritance through faith in Christ (3:26-28). Verse 29 applies that equal access: all who belong to Christ are Abraham's offspring and all are heirs. There is no "friends-not- heirs" subcategory in the Greek. The whole argument of Galatians depends on this being inclusive — if only a subset of believers inherit, Paul's rebuke of the Judaisers ("do not add ethnic or legal qualifications to the promise") collapses into its opposite. The doorstep form: "If everyone who belongs to Christ is an heir, what changes about the earthly/heavenly distinction the Watchtower draws?"