Supersessionism, also called replacement theology, is the Christian doctrine that the Christian Church has superseded the Jewish people, assuming their role as God's covenanted people, thus asserting that the New Covenant through Jesus Christ has superseded or replaced the Mosaic covenant. Supersessionists hold that the universal Church has become God's true Israel and so Christians, whether Jew or gentile, are the people of God.

In Judaism, the concept of the Jews as chosen people is the belief that the Jews as a subset, via partial descent from the ancient Israelites, are also chosen people, i.e. selected to be in a covenant with God. Israelites being properly the chosen people of God is found directly in the Book of Deuteronomy 7:6 as the verb baḥar (בָּחַר), and is alluded to elsewhere in the Hebrew Bible using other terms such as "holy people" as goy or gentile, Book of Exodus 19:6. Much is written about these topics in rabbinic literature. The three largest Jewish denominations—Orthodox Judaism, Conservative Judaism and Reform Judaism—maintain the belief that the Jews have been chosen by God for a purpose. Sometimes this choice is seen by believers as charging the Jewish people with a specific mission—to be a light unto the nations, and to exemplify the covenant with God as described in the Torah.