Everyone who accepts Christ is God's chosen people. And that's open to all -- Jews, Muslims, atheists, pagans, everyone.
1 Peter 2:9
But you are a chosen people, a royal priesthood, a holy nation, God’s special possession, that you may declare the praises of him who called you out of darkness into his wonderful light.
This is true , however, GOD still has an unbrakable Covenant with natural Israel.