johnny, no one says that the Church 'replaces' Israel.
We say that the Church IS Israel, it is the completion of and heir to ALL the messianic and eschatological promises made in the Old Covenant to national Israel.
If you view the covenant of redemption in a line, until Christ it was narrowly defined in terms of identification with a national entity, Israel, the children of Abraham through Isaac and Jacob. With the coming of Christ, and especially in the preaching of Paul to the Gentiles, this covenant was expanded, opened up, blown open, in fact to include the Gentiles. It, the church, contains both Jews and Gentiles...
To say that the church [i:6dee91fe9f]replaces[/i:6dee91fe9f] Israel is to tacitly accept that they are two different things; that before there was [i:6dee91fe9f]this thing[/i:6dee91fe9f], Israel and that now it has been replaced by [i:6dee91fe9f]this new thing[/i:6dee91fe9f], the church. No one says this...there aren't two different things, there is only one people of God called variously Israel or the Church.
The Reformers and many divines often referred to Israel, especially when she gathered for worship the church of the Old Testament. Likewise, the Church of the New Testament is called the true Israel of God.
Our charter is found all throughout Scripture but I would refer you especially to the first couple chapters of the epistle of Paul to the Ephesians.