I find it interesting that the Bible, particularly the New Testament, is accused of bias against/exclusion of both Jews and non-Jews/Gentiles. If these contradictory accusations can be leveled against the Bible, it's all the more likely that it's not biased against either group at all.
God's plan for revealing himself and extending salvation to the world has always included both Jews and Gentiles. The Old Testament makes it clear that the Jews were set apart as a nation in order to be witnesses to the entire world (see article on Gentiles in the OT). When the Messiah came, he first preached to the Jews; as the people set aside to be God's people and entrusted with God's words, they had the right to be the first people to meet the Messiah (Rom 3:1-2, 9:4-5). This was a strategic move as well: Jews who followed God and knew the prophecies of the Messiah would be the most ready to respond to Jesus and follow him, which is just what the twelve disciples did. Those first disciples could then spread the Gospel to others.
Though Jesus' earthly ministry focused on the Jews (Mt 15:24), he healed many Gentiles and even commended them for their faith (Mt 8:5-13, 15:21-28). The disciples were at first instructed to spread the word to their fellow Jews (Mt 10:5-7), yet even so they would be used as witnesses to Gentiles (Mt 10:18). And of course, after the Resurrection Jesus commanded them to preach to everyone (Mt 28:19, Ac 1:8).
The New Testament explains God's plan for Jews and Gentiles further. "The Gospel...is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile" (Rom 1:16). Paul explains in Ephesians 2:11-21 that Christ's death and resurrection results in Jews and Gentiles being united as Christians. Gentiles are no longer to be considered unclean (Ac 10:28) but are equal to Jewish Christians (Rom 10:12). Yet Jews are not discriminated against (see article on anti-Semitism in the NT): even Jews who reject the Messiah are to be "loved on account of the patriarchs" (Rom 11:28). Finally, just as the Jewish nation was to be a witness to other nations by their way of life, so Christians are to be witnesses by their actions as well as their words (Jn 13:35).
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