What was the first New Testament Scripture? It was one of Paul’s letters, probably Galatians or Thessalonians. This was written within 20 years of Jesus’ resurrection, around AD 48:
1 & 2 Thessalonians 1:1 (my translation, compare NIV)
Paul and Silas and Timothy, to the assembly of Thessalonians in God our Father and our Lord Jesus his anointed. Grace to you, and peace.
Did you notice the unusual address? In later letters Paul wrote to the church in Corinth or in Philippi. What did he mean by writing to the Thessalonians in God?
The nearest analogy is Paul’s familiar phrase in Christ. Christ is heaven’s anointed ruler for the earth. Consequently, our life is in him — in his cross, in his resurrection, in his enthronement, in his restorative authority, in his reign over the people of earth. The kingdom is in the king.
That’s how the people saw themselves even in the Old Testament times: in David (2 Samuel 19:43; 20:1; 1 Kings 12:16: ἐν Δαυιδ LXX). The anointed king represented the Lord’s reign, so the people lived in the joint authority of the Lord and his anointed (Psalm 2:2). Even when the kingdom fell apart and foreign kings reigned over them, God promised the restoration of these two thrones — the thrones of the Ancient of Days and the Son of Man (Daniel 7:9-14).
Is this the background for Paul’s phrase in God our Father and our Lord Jesus his anointed? Is he seeing the Thessalonian converts as living the joint reign of our heavenly sovereign (the Father of humanity) and the one we acknowledge as our ruler (our Lord) because he is heaven’s anointed (Christ)?
If so, we would expect to see this as the gospel Paul announced to the Thessalonians. Luke summarized the three weeks of Paul’s proclamation there like this: This Jesus I am proclaiming to you is the Messiah (Acts 17:3).
Now, that’s a very courageous proclamation to make in a military city that was proud of its imperial status. People interested in power could hear this as treason against the Emperor. They did. Paul and Silas were accused of defying Caesar’s decrees, saying that there is another king, one called Jesus (17:7). They fled for their lives under the cover of darkness (17:10).
And that was the occasion for this letter. They sent Timothy back to find out how these untaught new believers where coping, the collective gathering of Thessalonian people who exist in God our Father and our Lord Jesus his anointed.
So how does this kingdom interpretation of the phrase sit with Paul’s message in this letter?
We know that the assembly of Thessalonians included Jews as well as a large number of God-fearing Greeks and quite a few prominent women (Acts 17:4). Paul mentions how these non-Jews had turned to God from idols (1 Thessalonians 1:9). And his opening statement combines those whose heritage in the Abraham family goes back many generations with those who are freshly born into the family, all belonging together in the family that exists in God the Father of us all, belonging together in the reign of the Lord Jesus his anointed (1:1).
Together, these people exist in God and Christ, as they eagerly anticipate the reign of the Son whom the Father raised from the dead in order to rescue us from evil and restore us into his enduring reign (1:10). The kingdom theme (Christ’s reign) permeates these letters.
The joint authority of God and Christ is the locus of their life. Paul prays they will embody heaven’s kingship over the earth in the reign of the leader he has appointed for us: blameless and holy before God our Father in the presence of our Lord Jesus (3:13). That’s the same joint authority we saw in the opening verse: the eternal progenitor of us all (God our Father), and the ruler to whom he has given the kingship (our Lord Jesus Christ).
The church is the community that assembles around God’s throne and embodies his government on earth in Christ. As his kingdom, we exist in God our Father and our Lord Jesus his anointed.
I hope it inspires you as the people who exist in God and Christ. What could be more definitive for our identity and servanthood? It might be the earliest explanation of the church.
What others are saying
Ben Witherington III, 1 and 2 Thessalonians: A Socio-Rhetorical Commentary (Grand Rapids, MI: Eerdmans, 2006), 490:
What is especially interesting about this prescript is that Paul does not refer to a Christian assembly in a particular place as in almost all his later letters, but rather to a people, “the assembly of Thessalonian people” (see the similar phrasing in Col. 4:16: “the assembly of the Laodiceans”). Ekklēsia was not a technical religious term, though we often translate it “church.” For an audience overwhelmingly composed of Macedonian Gentiles “the assembly of Thessalonians” would have conjured up the old Greek democratic assemblies, which were called ekklēsiae. In common usage, ekklēsia was the coming together of the dēmos, not the group of people thus assembled. … One might translate it here “the gathered assembly of Thessalonians in God.”
F. F. Bruce, 1 and 2 Thessalonians, WBC (Dallas: Word, 1982), 7:
Here, however, the believing community in Thessalonica is not called the church of God, but the church “in God.” This is an unusual expression in the Pauline corpus, where otherwise “in God” is used of boasting in God (Rom 2:17; 5:11) or of being hidden in God (Eph 3:9; Col 3:3). On the other hand, “in Christ,” “in Christ Jesus” or “in the Lord” is a characteristic Pauline expression, especially when it has “incorporative” force, pointing to believers’ participation in Christ’s risen life or their membership in his body. If this is the force of the words “in … the Lord Jesus Christ” here, then “in God the Father” must be understood in the same way. …
In any case, the spontaneous joining of “God the Father” and “the Lord Jesus Christ” under a single preposition bears witness to the exalted place which the risen Christ occupies in the thoughts of Paul and his colleagues (cf. 3:11).
Leon Morris, 1 and 2 Thessalonians, TNTC (Downers Grove, IL: InterVarsity Press, 1984), 42:
Also peculiar to these epistles is the phrase in God the Father and the Lord Jesus Christ (Paul usually says ‘in Christ’). It is striking (a) that he speaks of the Father and the Lord in one breath (no-one else could be linked with the Father in this way), (b) that he joins the two under one preposition in, and (c) that he expresses the closeness of the tie linking the Thessalonians with their God in terms of Christ as well as the Father. ‘The association could hardly be closer’ (Ward). This high view of Jesus is continued with the use of Lord and Christ. Lord was used in lxx as the translation of the divine name and it was commonly used of deity in other religions (as well as having less significant uses). It points to a very high place. Christ means ‘anointed’ and is equivalent to ‘Messiah’. And all this in a letter written only about twenty years after the crucifixion. From very early times Jesus was seen to have the highest place.
Chrysostom, “First epistle of St. Paul the apostle to the Thessalonians, Homily I” in Nicene and Post-Nicene Fathers of the Christian Church, 13:324:
For there were many assemblies, both Jewish and Grecian; but he says, “to the (Church) that is in God.” It is a great dignity, and to which there is nothing equal, that it is “in God.”