How do we know God's people include Gentiles?

Scriptural passages such as Isaiah 42:6 affirm that the promised Messiah would be a light to the Gentiles, indicating that God’s plan of salvation transcends ethnic boundaries. Zechariah 9 emphasizes how even the Gentile nations become willing to serve God in the day of His power, highlighting God's grace towards all humanity. In Revelation 7:9, John sees a multitude from every nation, a clear representation of the diversity of those who make up the Israel of God. Paul's letters further emphasize that in Christ, there is neither Jew nor Gentile, as all believers are united in Him (Ephesians 2:14-16). Thus, the inclusion of Gentiles in God's redemptive plan is firmly established in Scripture.