In Christ Jesus you are all children of God through faith. As many of you as were baptized into Christ have clothed yourselves with Christ. There is no longer Jew or Greek, there is no longer slave or free, there is no longer male and female; for all of you are one in Christ Jesus. And if you belong to Christ, then you are Abraham’s offspring, heirs according to the promise. (Galatians 3:26-29, NRSV)
Paul has abruptly changed to the second person plural to show that his readers should take personally the following verses. The apostle takes the honorific phrase, "sons (children) of God," from the Jews who would only get this title at the Last Judgment directly from God, and bestows this status on Gentiles who believe now.