Naomi,
Certainly, Romans 11:25 is a key passage in understanding what Paul is saying. Unfortunately, I don't think this is translated well in many Bibles and therefore is a bit misleading. The word in question here is πλήρωμα. Many translations give this word a numerical connotation, (full number, full completed number, etc) but is talking about the full spiritual blessing that is now being poured out upon the Gentiles in Christ. This same word is used in similar contexts in passages like John 1:16, Rom 15:29, and Eph 3:19.
In fact, I think Paul is basically restating what he has already said in verses 11 & 12 when he writes:
11 So I ask, did they stumble in order that they might fall? By no means! Rather, through their trespass salvation has come to the Gentiles, so as to make Israel jealous. 12 Now if their trespass means riches for the world, and if their failure means riches for the Gentiles, how much more will their full inclusion mean!
The word translated "full inclusion" is also this word πλήρωμα. So, clearly Paul here is not talking about a numerical quantity of Israelites but the fullness of God's mercy and invitation to them to find life in Christ. In the same way, in verse 25, Paul is saying that God hardened Israel until the fullness of his blessing has εἰσέρχομαι (arrived, come, come in) for the Gentiles. So again, the point here is not (as many Dispensationalists put it) that God has a church age where he saves Gentiles and then turns off that valve of grace (perhaps in the rapture) so he can turn on the valve of grace to save all of national Israel. The point is that God has hardened Israel for a time and has chosen this time to fully include the Gentiles in his grace and mercy so as to make Israel jealous. As a result of this full blessing poured out on the Gentiles, God aims to use that as a means to pour our his full blessing and inclusion on Israel as well.
So, you may disagree, but I still maintain this is not about eschatology, but about God's current plan in Paul's day to save both Jews and Gentiles.
To answer your question, "No, I don't believe there will be a time when God is done with the Gentiles." According to Paul, those walls are now broken down. God's people are no longer the result of flesh and blood or genealogy. God sees his children as those of faith. Those who have the faith of Abraham are children of Abraham and there is no longer Jew or Greek. We are all one in Christ. That is why the dispensaiontalist system is particularly bothersome to me. It seems they want to erect walls of division based on flesh when Christ has intentionally torn down those wall so that "true Israel" are those who are born of the Spirit, not born of flesh. I think that is the overarching thrust of Paul's teaching in Romans 9-11, and yet some has used these passages to teach quite the opposite of what Paul was trying to communicate! Paul is talking about God's sovereign choice to make a person's faith the means by which he designates his children, and people have used these chapters to teach predetermination and God's special focus on a people based on their flesh, not their faith! Very disappointing in my mind.
I agree with you that Romans 11:25-26 is badly translated.
The Gentiles mentioned in verse 25 are the heathen Gentiles, and not the "Christian Gentiles" as many assume the case to be.
Paul is telling the Christian Gentiles when Israel will be redeemed/saved.
A better translation of the Greek text is: -
Romans 11:25-26: - 25 For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel, ἄχρι (until the fullness with respect to time) οὗ (That) τὸ (the) πλήρωμα (fulfilling) τῶν (of the) ἐθνῶν (heathen gentiles {trampling the sanctuary for 2,300 years}) εἰσέλθῃ, (is completed,) 26 after which all Israel will be saved, . . .
This is confirmed by Luke 14:31-32.
Also "
ἐθνῶν
" can be traced all the way back to Genesis 10 and the formation of the Heathen Gentile nations.The above paraphrasing of Romans 11: 25-26a is a far better understanding of what Paul wrote than the forced "Gentile Church" understanding of the translators and the subsequent adopted tradition of 'the fullness in numbers of the "Gentile Christian" coming into the church.' If Paul was referring to the Christian Gentiles in verse 25 then he would have used the Greek word "ἔθνεσιν" which he uses to address the Christian Gentiles such as in Romans 11:11 and 13 etc..
It is certainly much food for thought.
Shalom