Here’s another insightful quote from Matthias Konradt’s recent book Israel, Church, and the Gentiles in the Gospel of Matthew (Baylor-Mohr Siebeck Studies in Early Christianity) on the difference between “Israel” and the “church” in Matthew.
Jesus’ people (ὁ λαὁς αὐτου) and his church (μου ἡ ἐκκλησία) are not identical. Rather, the narrative indicates that Israel and ecclesia are situated on different soteriological levels: Israel appears as the addressee or recipient of God’s salvific act in Jesus Christ (Matt 2.6; 4.16, 23; 15.24)–and remains so, even after Easter. The ecclesia, in contrast, is the community that emerged in the course of the diverging reactions to Jesus in Israel (and is further formed from the nations or continues to develop with members from Israel as well as Gentiles)–a community of those who have seized the chance for salvation by entering into discipleship and are, at the same time, obligated to continue to pass on God’s “offer of salvation” to Israel (and the nations). In light of the plurality of pre-Rabbinic Judaism, rightly emphasized in recent scholarship in Jewish studies, the differentiation between Israel and an individual group outlined here fits well with the larger picture of Judaism. The Christ-believing ecclesia claims sole possession of the true awareness of God and God’s will. Nevertheless it is problematic to characterize the ecclesia as “true Israel,” as this identification could suggest the mistaken conclusion that non-Christ-believing Judaism is no longer “Israel.” (345)