Point in case, your paradigm prevents you from seeing that which us clearly obvious as it relates to the topic of the thread.
Jeremiah 18 is saying that if a nation, whom He has promised to establish and build up, rejects Him, He will not establish and build up that nation.
Thus is exactly what happened in the year following Jesus' ascension, from Acts 1-9. Jesus promised to return and establish His Kingdom, Israel as a nation rejects Him, Jesus cuts off israel, setting His plans for them aside to work with the Gentiles until the fullness of the Gentiles has been reached, after which He will resume working with Israel. This is why Paul was chosen, instead of sending the 12, because to reach those who didn't know any law, one had to teach a message the excluded the Law. The twelve only knew the law, and nothing else, as a means of salvation. Hence why Jesus revealed the mystery to Paul, and why Paul's message is completely different that the twelve's.
[MENTION=2589]Clete[/MENTION]
Some thoughts on that part in bold...
Neither Paul, nor the Mystery, nor the Body are a replacement of Israel's own commission to the Gentiles.
Neither are they in answer to Israel's fall, which was Prophesied, in Daniel 9; etc.
Rather, Paul; the Mystery he alone preached and wrote of; and its' New Creature: the Body of Christ, are a different aspect of God's plan and purpose.
Israel's commission to the Gentiles is after the Lord returns in His Wrath, followed by His Blessing of Israel into their Prophesied Priesthood, Isaiah 2; Isaiah 66; etc.
Their Prophet Daniel, foresees a gap in time between Israel's fall and the Lord's return, Daniel 9 and Daniel 12.
That is the Mystery of God, it has to do with God's plan and purpose to reconcile this fallen Earth back unto Himself, through a redeemed Nation Israel, one day, Eph. 1:10; Col. 2:2; Rev. 10:7, and so on.
In contrast, there is the Mystery of Christ, which is a different plan and purpose that has to do with God's plan and purpose to reconcile those fallen Heavenly Places mentioned in Eph. 6, back unto Himself through a New Creature: the Body of Christ, which is comprised of BOTH formerly LOST Gentiles AND formerly LOST Jews this side of Israel's fall in Acts 7 and calling of Paul in Acts 9, see Eph. 1:10; Eph. 2; Col. 2:2, and so on...
Ephesians 2 describes both agencies.
Formerly lost Gentiles and Jews in the Body being the Father's Heavenly agency, and the Commonwealth of Israel being His Earthly agency.
Both fellow citizens, each within their respective realm within God's kingdom.
Together, both these aspects are the Mystery of the Father, Eph. 1: 10; Eph. 3:15; Col. 2: 2.
Colossians 2:1 For I would that ye knew what great conflict I have for you, and for them at Laodicea, and for as many as have not seen my face in the flesh; 2:2 That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ; 2:3 In whom are hid all the treasures of wisdom and knowledge.
Rom. 14: 5 towards you, JR - in memory of Rom. 5: 6-8 - in each our stead.