1 Peter 2:9-10 (ESV)
But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light.  Once you were not a people, but now you are God's people; once you had not received mercy, but now you have received mercy.
You are a chosen race, a royal priesthood, a holy nation. This is what we are as Christians, no longer are we Greeks or Jews, No longer are we Germans, Swedes, Norwegians, Zulu, Tshwane, Korean or Japanese, but we are a chosen race, a royal priesthood, we are Christians saved by the grace of Christ. To be sure we won’t in this life, and perhaps not even in the next shed all of our cultural heritage and that isn’t the point. The point is first and foremost we are Christians, even if we don’t always think in those terms.
We belong to a priesthood, a royal one at that. That is how peter describes us, words he received from the Holy Spirit, words he received from Christ. And the purpose of us being in this priesthood is to proclaim the excellencies of him who called us out of darkness into his marvelous light. That is to praise God, and show his mercy, his light to all those around us.
Once we had not received mercy. At one time we were cut off from God’s mercy. But God then sent his Son, to be the glory of his nation Israel, and a light to the gentiles. And is he both! We have received mercy. We have received salvation. We have received his light.