The Jews were called God’s chosen people because he chose them to bring forth the Messiah, Jesus Christ. After Jesus died for all of us, we too became God’s chosen people.
We are Christ’s bride. You take upon yourself your husbands tribal identity when you marry Him. We have become one with Christ. Jesus Christ is the lion of the tribe of Judah. Since we are the bride of Christ, we belong to the tribe of Judah, because He will always be identified as the primary member of the tribe of Judah. We may not become true members of the tribe of Judah until after the marriage feast.
Many, and even possibly most people in the Church are the gathered from the lost tribes of Israel. Many of us are Jacobs descendants. We just don’t know it, but The LORD has kept track of who we are. Many, after the tribulation, will be utterly surprised that they of Israel, and gathered back to her, with permanent residency in the land Israel. God is always keeping His promises to Abraham. In the very least many of those The LORD has chosen are children of Abraham.