At the end of 2 Corinthians 6, Paul quotes a series of Old Testament texts in support of his exhortation, “Do not be bound together with unbelievers.” God’s temple has no agreement with idols, and the Christian and the church are temples (v. 16). The church fulfills Yahweh’s promise to dwell and walk among His people (v. 16b; quoting Leviticus 26:12 among other passages). Because the Lord dwells in the church, Christians must “come out from their midst and be separate” and avoiding touching anything unclean (v. 17, quoting Isaiah 52:11).

Verse 18 raises several questions.

First, verse 18 changes the framework; it is not about temples, the Lord’s dwelling, or uncleanness, but about fathers, sons, and daughters. Paul moves from temple language to household/familial terminology. He make the reverse move in Ephesis 2:11-22, moving from talk of strangers, aliens, household to explicit temple and priestly language. These passages together (and there are probably others) suggest that in Paul’s mind household language and temple language are identical or at least parallel. That suggests that the “sonship” language of Paul’s letters has priestly undertones.

Second, verse 18 ends with a “says the Lord Almighty,” but the specific statement of verse 18 is not found anywhere in the Old Testament. The closest the OT comes to this is in 2 Samuel 7 and 1 Chronicles 17:13, both of which record Yahweh’s covenant promises to David. Yahweh explicitly says that He will be father to David’s son, Solomon; but Paul expands that to say that the Lord promises to be a father to every believer, considered as “sons and daughters to Me.”

The Christo-logic of this use of the Davidic covenant is pretty clear: Jesus is David’s Son, the greater Solomon; in Him, all believers are sons and daughters of a heavenly Father, the God of Israel. Given the Davidic covenant echoing in the background, Paul is saying that believers are royal sons and daughters, princes and princesses in Yahweh’s house. And, since that house is a temple, He is saying that we are priests as well as kings, priestesses as well as queens.