Response: There is absolutely nothing said about Paul's "preaching about the Millennial Kingdom" in Acts 28:23. Paul was talking to these Jewish men about the kingdom of God and who Jesus is. Both of these subjects can be found in Paul's prison epistles, so why think Paul is "preaching about the Millennial Kingdom" here? Since it was Jewish men to whom he was speaking, Paul appropriately used the law of Moses and the prophets in his attempt to persuade them concerning Jesus (i.e., concerning his identity as the Christ and Son of God). But so what? There is nothing about Paul's evangelistic efforts here that is in any way inconsistent with the administration of the grace of God that was given to him. Jesus' being the Christ, his being of the seed of David and his resurrection was according to Paul's evangel both before and during his imprisonment (2 Tim 2:8-9). So how is Acts 28:23 in any way supposed to support the view that Paul was "preaching the Millennial Kingdom" at this time? We have, instead, good reason to believe that Paul was hoping that these Jews would (after being persuaded concerning who Jesus is) believe his evangel of the uncircumcision (as Paul himself had believed it), become members of the body of Christ (where there is neither Jew nor Greek, slave nor free, male and female, for [we] are all one in Christ Jesus" - Gal. 3:28; cf. Col. 3:11), and deem the things that Paul once considered a "gain" (i.e., his status as an Israelite) a "forfeit" (Phil. 3:4-8).
Response: The body of Christ in 1 Cor. 12 is nowhere said to be "inseparably connected with gifts." Paul's ministry one year before his imprisonment and one year after it involved the same gospel and the same body of Christ. The spiritual gifts given to Paul and those who believed Paul's distinct gospel (the "evangel of the uncircumcision") were signs to the circumcision that God was doing a new work through Paul to build a new thing: the body of Christ. Tongues were a sign for those among the circumcision who did not believe God was working through Paul and the Gentiles who believed his gospel (1 Cor. 14:22). Paul's miracles (both the miracles he performed himself and the supernatural gifts that were given to others through him) were the signs of his special apostleship from the Lord (2 Cor. 12:12; Gal 2:7). Without such supernatural signs, neither Peter, the saints in Jerusalem, nor any other Israelite would have been assured that God had commissioned Paul to bring salvation to the Gentiles (Acts 9:15; 15:12; 22:21).
In connection with this point, it was the spiritual gifts possessed by the apostles that enabled the Scriptures to be both written and identified by believers at this time (1 Cor. 14:37). The closer we get to Paul's completion of the inspired canon of Scripture (which took place during his imprisonment), the less miraculous activity we find taking place (2 Tim 4:20). But even in 1 Timothy we still read of the "laying on of hands" (1 Tim 5:22; cf. Acts 19:4-6; 2 Tim 1:6-7). Once all Scripture was complete and the canon was established, there was no more need for further supernatural manifestations of the spirit. Paul knew that the miraculous gifts would not last among the body of Christ and, as early as his epistle to the Corinthians, began immediately preparing the body of Christ for the time when they would vanish (1 Cor. 13:8). Only faith, hope and love were going to remain. Remain among whom? The body of Christ, of course! The body of Christ referred to in this epistle did not vanish when the supernatural gifts did. It simply attained to a greater level of maturity. Certain gifts disappeared, yes, but the body of Christ itself did not.
That the body of Christ underwent a process of growth into further maturity as the Scriptures were being completed is evident from Ephesians 4, where the only gifts in the body of Christ referred to are those of being apostles, prophets, evangelists, pastors and teachers. Notice how the supernatural gifts listed in 1 Cor. 12:28-29 (such as the power to heal and speak in tongues) are conspicuously absent. And even those who believe that the gifts of prophecy or evangelism or teaching were not present in the body of Christ when Paul wrote Ephesians must admit that they were present in the body of Christ at one point, since Paul says that these particular gifts were given "toward the adjusting of the saints for the work of dispensing for the upbuilding of the body of Christ, unto the end that we should all attain to the unity of the faith and of the realization of the son of God, to a mature man..." (4:12-13). Similarly, Paul speaks of there being both apostles and prophets within the body of Christ in Eph 3:5. Again, certain gifts disappeared in between Paul's writing to the Corinthians and his writing to believers from prison, but the body itself continued, simply growing in maturity.
Objection: "In Paul's epistle to the Corinthians, the "body of Christ" to which Paul referred was a local body only. Christ was not the head of this body. The head of this body is composed of some of the members of the Corinthian church ("The eye cannot say to the hand...")."
Objection: "If, during his Acts ministry, Paul didn't expect the second coming of Christ to take place within his lifetime, then why did he speak of the Thessalonian believers as "waiting" for his Son from heaven (1 Thess 1:10)? He also expected to be "raptured" with these saints, for he wrote, "then WE WHICH ARE ALIVE AND REMAIN shall be caught up together with them in the clouds." This epistle was written circa 49-51 A.D.
Response: For Paul, the snatching away of the body of Christ could occur at any time. It would be begging the question to understand 1 Thess 1:10 to be a reference to Christ's coming to earth to set up the millennial kingdom. As far as what Paul said in 1 Thess. 4:13-18, if these words should be understood to mean that Paul expected the snatching away to necessarily take place within his lifetime, then I submit that these words would ALSO have to mean that Paul expected himself and everyone to whom he wrote to be alive and surviving at the time, since he says, "..we, the living, who are surviving to the presence of the Lord, should by no means outstrip those who are put to repose..." and "...we, the living who are surviving..." But does the objector really think that Paul was convinced that he would, without a doubt, be among "the living who are surviving to the presence of the Lord?" I doubt it. But according to the reasoning of the objector, this conclusion would seem to follow.
I think a more reasonable interpretation is simply that, because Paul and those to whom he wrote were obviously alive at the time he was writing, he includes himself and other living believers as being in, and representative of, that particular category of believers that he has in view (i.e., those believers who will be alive and surviving when the snatching away takes place). I don't think Paul expected to necessarily be in that category of believers who are "alive and surviving" when Christ comes to remove the body of Christ from the earth before the coming "day of the Lord." As far as Paul knew at this time, it could've been the Lord's will that he (as well as those to whom he wrote) be martyred prior to this event, and would thus be among the "dead in Christ" at the time.