1 Corinthians 9:20

9:20 To the Jews I became like a Jew to gain the Jews. To those under the law I became like one under the law (though I myself am not under the law) to gain those under the law.

1 Corinthians 1:22-24

1:22 For Jews demand miraculous signs and Greeks ask for wisdom, 1:23 but we preach about a crucified Christ, a stumbling block to Jews and foolishness to Gentiles. 1:24 But to those who are called, both Jews and Greeks, Christ is the power of God and the wisdom of God.

1 Corinthians 10:32

10:32 Do not give offense to Jews or Greeks or to the church of God,

1 Corinthians 12:13

12:13 For in one Spirit we were all baptized into one body. Whether Jews or Greeks or slaves or free, we were all made to drink of the one Spirit.