I will restate what I wrote in response:
The church of God that Paul persecuted is made up of those believers (Jew and Gentile) who believed on the name of Jesus and believed the gospel of the kingdom, the prophetic kingdom on earth. They are in Christ.
These are the pre-Pauline believers you spoke of.
In the dispensation of grace the church of God is the body of Christ, revealed through Paul, the church where the Jew and Gentile has become one new man and will be in heavenly places. The body of Christ was not formed before this dispensation. They too are in Christ.
As far as the resurrection, both churches of God have part in the first resurrection. This resurrection is in two parts:
1st part of the resurrection; the dead in Christ in the body of Christ will rise first (
1 Thessalonians 4:16) then we who are alive in the body (
1 Thessalonians 4:17). The body of Christ will be risen to take position in the heavenly places.
2nd part of the resurrection; The believers in the church of God in Christ before this dispensation of grace, the tribulation saints, and the old testament saints, will be resurrected to enter the kingdom on earth.
These are the pre-Pauline believers you spoke of.