Who Do We Belong To? Who Are We?

I Peter 2:9:

⁹ But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light; ¹⁰ who once were not a people but are now the people of God, who had not obtained mercy but now have obtained mercy.

¹¹ Beloved, I beg you as sojourners and pilgrims, abstain from fleshly lusts which war against the soul, ¹² having your conduct honorable among the Gentiles, that when they speak against you as evildoers, they may, by your good works which they observe, glorify God in the day of visitation.

I think we cannot ask and answer this question of identity without reference to I Peter 2:9-12. In a sense, perhaps, we are like Israel, but not at all. Some of the words are similar, but the relationship is completely transformed, It is spiritual and real rather than physical and real only in human or genetic terms.  "Not all Israel was Israel," Paul wrote.

I've been thinking about identity, purpose, basic questions, and if one is a believer this must be the beginning. I used to hear people say "I am not a Christian writer (or teacher, or accountant, or whatever); I am an X who happens to be a Christian." Well, that's stupid. It's backward, and non-theological. "I am a Christian (first, not by happenstance but divine and human appointment) who practices and finds fulfillment in writing, or teaching, or accounting, or whatever." I don't happen to be a writer; it is my joy and gift, from God and to others, I hope. Christian first, always. Or not a Christian at all.