So, Christianity holds that Christians are Israel! That's called Replacement Theology which stands for vandalism of the gospel of Jesus aka the Tanach with the things of the gospel of Paul aka the NT. I am glad you said that yourself because, the other day, a Christian on denial asked me for an evidence that Christianity holds that Christians are Israel. Has HaShem ever said that Christians are My son? I don't think so! Has HaShem ever said that "Israel is My Son?" Read Exodus 4:22,23.
Actually it's called 'Covenant Theology'- 'replacement theology' is derogatory and stated largely by a group of Christian 'dispensationalists' who think there are multiple covenants. It's 19th Century heresy which gained speed mainly in America.
It's essentially Christian-Zionism.
The Protestant Reformation adopted Covenant Theology, which is appropriately a
reformed version of the Roman Catholic Church's 'Covenantal Dogmas'.
It is nothing new, and quite frankly your argument stands knee high to an ant in relevance. They knew the literature far more than you, as these dead languages weren't so dead then and the histories were still relevant