In our day there exists much confusion regarding the identity of the true people of God. Some conceive of the church as a mere parenthesis in the plan of God — an afterthought brought about by ethnic Israel’s rejection of Christ. For these people, the authentic people of God are the physical descendants of Abraham.
Others say that the church has replaced Israel in the plan of God. Older proponents of this view have tended to say that with the church, God has exchanged the Gentiles for the Jews.
While both groups of people would affirm the necessity of Christ for salvation, neither is the biblical view. Either way, the fundamental unity of the people of God across the ages is denied. Whether it is said that the church is an afterthought or that the church replaces Israel, both views implicitly affirm that there are two different ways of salvation, one for the Jews and one for the Gentiles
However, the Bible teaches that there is but one people of God and only one way of salvation. In 1 Peter 2:9, Peter calls his mostly Gentile audience “a royal priesthood, a holy nation, and a people for his own possession.” These are all terms used for the nation of Israel in the Old Testament (Ex. 19:5–6; Isa. 43:20–21), and Peter applies them to the church because the church is the true Israel of God.
The biblical view (which is sometimes mistakenly called “replacement theology”) does not say that the church “replaces” Israel. Rather, it affirms that true Israel always was, always is, and always will be comprised of those who trust in Christ alone for salvation. This is plain from 1 Peter 2:10. The Gentiles, who were formerly not God’s people, are now God’s people because they have trusted in the Messiah and because they worship Israel’s true King.
Old covenant believers were likewise able to be the people of God because they were in Christ. Though they lived before the Son became incarnate, they looked forward to the day in which He would come, and they trusted in Him (John 8:56). Their example likewise shows us that the true Israel of God has always been comprised of those who love and serve the Messiah.
That the church is the Israel of God does not mean that every church member has authentic faith. Throughout history, the visible church has always included those who are not true believers because of their inauthentic faith (Rom. 9:6–7). However, in Christ, God is fulfilling all of the promises made to Israel. As the people of God, we must fulfill the task of Israel and proclaim God’s excellency (1 Peter 2:10). Seek to do this in whatever you do.