Yesterday was the Epiphany, when we particularly remember the revelation of Christ to the Gentiles. For those of us who are Gentile Christians, I think there are at least four good reasons to think more about our Gentile identity.
1. It keeps us humble. We were not people who were close to God - rather, we were separated from Christ, without God. If we get a taste of the blessings of the gospel, it is as dogs gathering up the crumbs under the table.
2. It reminds us of God's grace. It is remarkable that repentance and life have been granted even to the Gentiles. Unlike the people of Israel, we were in no way prepared for the reception of this gift. Unlike the people of Israel, we had no obvious interest in Christ. If God has revealed himself to us - even us Gentiles - in Christ, then it can only be his free grace.
3. It keeps us focussed on Jesus. We are certainly not the 'true Israel', the real people of God. Neither is 'Israel' the 'true Israel'. Rather, Jesus the Messiah is in his own person the only true Israel, the only one who truly kept the covenant, lived out his election, acted for and to God in faith and faithfulness. If we are the people of God in any sense, it is only because we are joined to him by faith.
4. It helps us to remember that we are not the final goal. Just as Israel needed to remember that they were not called not only for their own sake but also for the salvation of the world, so we Gentile Christians need to remember that if we have been called it is ultimately for the salvation of Israel. Getting this right is the key to remembering that in general we are called for the sake of others, and not just to rest in our undeserved privileges.