In his article "The Readjustment Administration," Adlai Loudy references Ephesians 2:12 in support of the position that, during the time period prior to Acts 28:28, the nations were subservient to the nation of Israel. In this verse, Paul tells us that the nations to whom he wrote were "in that era, apart from Christ, being alienated from the citizenship of Israel, and guests of the promise covenants, having no expectation, and without God in the world." But what "era" is Paul talking about here? Is it the time period from Acts 13:2 to Acts 28:28 (which Loudy refers to as the "readjustment administration")? I don't think so.
How could anyone who is "in Christ," "a new creation" and "conciliated to God" (2 Cor. 5:17-18) be, at the same time, "without Christ" and "without God in the world?" Would this not be a contradiction? It seems far more likely that the "era" Paul has in view in this verse is simply the time period which he describes at the beginning of chapter 2 - i.e., the time during which those to whom he wrote were walking in their offenses and sins, "in accord with the eon of this world, in accord with the chief of the jurisdiction of the air" (Eph. 2:1-2). The "era" Paul has in view can therefore be understood as the time period prior to when the evangel of peace came to them (Eph. 2:17) and they heard and believed the word of truth, the evangel of [their] salvation (Eph 1:13). If this is the case, then this verse has nothing to do with an inferior, pre-Acts 28:28 administration. Paul is simply referring to their life before they believed his gospel and became members of the body of Christ.
But what is the "citizenship of Israel," from which the nations were "alienated" during the era that Paul has in view in Eph 2:1-3? The word "citizenship" (politeia) is only meaningful if a particular political entity - i.e., a nation or city - is in view. But what political entity? When this article was first posted on my blog, I argued that the political entity to which this "citizenship" referred is the new Jerusalem. However, I now believe I was guilty of overthinking this a bit, and reading too much into what Paul was saying here. Paul was not, I don't think, referring to a political entity to which Israel belonged (or rather, will belong in the future). Rather, Israel itself - i.e., the nation comprised of Israelites - was the political entity he had in mind. Paul was simply saying that those among the nations as such (i.e., those "termed 'Uncircumcision'") were not - and could not be - citizens of Israel while uncircumcised. And being thus "alienated from the citizenship of Israel," the "promise covenants" that God made with Israel which pertain to the promised blessings that Israel will enjoy during the eons to come (such as the Abrahamic covenant, the Davidic covenant and the new covenant) were not made with them, and did not directly pertain to them. Any blessing that Gentiles will enjoy in the eons to come because of these covenants made with Israel will come only through Israel.
It was because of their status as uncircumcised people of the nations (rather than Israelites) that Paul could thus refer to them as "guests" of these promise covenants. The Greek word translated “guest” here is xenos, and literally means “stranger” or “foreigner”; only by implication does it mean “guest” (in certain contexts). That the word could mean “stranger” as well as “guest” is clear from the fact that Knoch translated this word as “stranger” more often than “guest” (see, for example, Matt. 25:35, 38, 43, 44; 27:7; Acts 17:18; Heb. 11:13; 13:9; 3 John 1:5). However, whether translated “stranger” or “guest” in Eph. 2:12, the imagery Paul was using can simply be understood as conveying the idea that, because the nations were not "citizens of Israel" (those with whom the covenants had been made), they had no inherent privileges with regards to enjoying covenant-based blessings. Any blessings a Gentile will enjoy due to God's fulfilling his covenant promises to Israel will be received indirectly, through the mediation of those with whom the covenants had been made.
The answer to this question gets at the heart of the "secret" of this present administration. The nations to whom Paul wrote (along with some Jews, like Paul himself) had become members of "the ecclesia which is [Christ's] body" (Eph. 1:22-23), which is a new corporate entity distinct from Israel and her expectation. They had "in one spirit," all "been baptized into one body, whether Jews or Greeks, whether slaves or free," and all were made to "imbibe one spirit" (1 Cor. 12:12-13). Having become members of the body of Christ (v. 27), they had become part of a "new humanity" where there is "no Greek or Jew, Circumcision and Uncircumcision, barbarian, Scythian, slave, freeman" (Col. 3:11; see also Gal. 3:28). When those to whom Paul wrote believed his distinct "evangel of the uncircumcision" they (we!) received a new eonian expectation and allotment. This eonian allotment is "in the heavens" (2 Cor. 5:1-2) and "among the celestials" (Eph 2:6). It is not associated with the "citizenship of Israel," but is entirely distinct from it.
In addition to Ephesians 2:12, Paul's words in 1 Corinthians 16:1-4, 2 Corinthians 8-9 and Romans 15:25-32 are viewed by proponents of the Acts 28:28 dispensational theory as being in conflict with the position that the Gentiles who believed Paul's gospel before his imprisonment had, during this time, an eonian allotment distinct from Israel's. In these passages, Paul speaks of making financial contributions to, and taking up a collection for, the poor saints in Jerusalem. Can we account for this without appealing to the view that the Gentiles in the body of Christ were, before Paul's imprisonment, dependent on Israel for their eonian allotment, and were to have an inferior and subordinate place in the millennial kingdom? I think so.
In Galatians 2, Paul recounts the private meeting he had with Peter, James and John in Jerusalem, concerning his commission. In verses 9-10, Paul writes, "...knowing the grace which is being given to me, James and Cephas and John, who are supposed to be pillars, give to me and Barnabas the right hand of fellowship, that we, indeed, are to be for the nations, yet they for the Circumcision-" only that we may be remembering the poor, which same thing I endeavor also to do." Concerning this agreement between the apostles, A.E. Knoch writes, "There was a mutual understanding arrived at among them that they [Peter, James and John] would confine themselves to the Circumcision, while Paul and Barnabas went to the nations. This agreement should have kept the judaizing disturbers of the Galatian believers from interfering with them. Paul kept his part of the compact, especially that which concerned the collection for the poor saints in Judea."
For the reasons given above, the "spiritual things" (spiritual endowments/gifts) in which the nations participated were for the blessing and edification of the body of Christ (not Israel) - and that, only for a temporary period of time. The "spiritual things" in which the body of Christ participated were simply a means to an end, and that end had nothing to do with the preeminence of Israel over the body of Christ (either at that time, or in the future), or with Israel's eonian allotment. Rather, they had to do with the formation of the body of Christ through the sign-accompanied apostolic ministry of Paul, and with the progressive completion of God's written revelation to the body of Christ, through Paul.
 Another possibility is that the gift of languages was meant to be a sign to those Jews who, although having been converted through the ministry of the twelve apostles, did not believe (or would not have believed) that God was working through Paul to form a new body of believers consisting primarily of Gentiles, and that God was among them. Understood in this way, this gift would've served a similar purpose as the other gifts which served to legitimize Paul's apostleship, ministry and message.