Why Do Calvinists Usually Believe in Replacement Theology?

A Calvinist, usually, not always, believes in replacement theology; that is, the Church replaced Israel, rather than maintain Israel will become the center of all nations when Jesus returns in Person to reign on earth during the 1000 years. The truth though is the reward is given to overcomer believers (Jude 14,15) to reign as kings and priests with Christ before the New City commences. In other words, the Church receives beforehand God's promise before Israel does; that is to say, Israel, like other nations, still requires individuals to be saved within its nation who will become the inhabitants of the New City and New Earth after the millennial reign. There is no replacement because just because you lived in Israel doesn't mean you were automatically saved. Israel broke its covenant with God, so God deals accordingly by giving the promise to the Church.

Well I can think of one reason why replacement theology is attached to Calvinism. Calvinism came out of the Roman Church under Augustine and did not exist prior to then during the 3 centuries after Christ. Augustine could not let go of some of those false teachings like amillennialism when he introduced his new teaching of Calvinism. Like in Geneva under Calvin, amillennialism is very controlling over people, so naturally amillennialism plays right into controlling people by trying to claim Jesus is reigning now with a rod of iron. But this is a false Christ because Jesus has not returned with His overcomer believers (5 wise virgins, Matt. 25.1-12) who come "out of" the Church. Those who overcometh who are "taken" at the start of the Tribulation (Matt. 24.42, Luke 21.36, Rev. 3.10) and at the last trumpet before the bowls are poured in the last 24 months of the Tribulation (a portion of those in 1 Thess. 4.15-17 who are "left" are also rewarded with reigning as shown in Rev. 20.4) for all to see as we wait, are all those in Christ who are prayerful, keep the word of His patience and are watchful for our imminent rapture.

Though there are other reasons, I think this is the main reason. Man in his flesh likes to control other men; whereas God says the Church is meek and lowly. There is no Pope of Geneva or Rome, but there are Apostles who work regionally who appoint Elders of each locality. In so doing, you find each church locality is responsible unto itself and does not spread false teachings like a wildfire across regions and countries and continents as would exist with the Calvinist denominations and if amillennialism were true.

Performance really takes over for a Calvinist (but not for the sake of the gospel for all), because he is never sure if he is really saved or not since it was never his choice, so he thinks. It was irresistibly imposed on him, but there are no real markers to know if he really does believe. So he works for it (perseveres instead of the choice to believe by faith) and hopes that is good enough, just like the Roman Church teaches. This is not surprising since the men of Calvinism come out of the Roman Church and share infant baptismal regeneration usually like Calvin did. Calvin believed he was born-again when he was baptized as a child. Christians do not believe these false teachings.