A few months ago I met a very intelligent man who is greatly interested in the Torah and the Old Testament Scriptures in general, as well as being a professing Christian. We spoke about the Hebrew language and the common interest we have of it, and then he proceeded to invite me to practice reading Hebrew. Through e-mail he sent me the reading material as well as a doctrinal statement of what he believes. His statement included several Old Covenant laws that he thought we should be following, from dietary laws to following the Sabbath, and many more in between. This got me thinking more in depth about Christianity's Jewish roots and the obvious question follows, "How Jewish should a Gentile Christian be?"
One of the first statements this friend made was that God made an unconditional covenant with Abraham concerning his seed. Those who bless his seed will be blessed, and those who curse his seed will be cursed (Gen. 12:1-3). This leads my friend to be very desirous to bless Jews, which is a good desire. But who exactly is the seed of Abraham, simply ethnic and/or religious Jews? I think the New Testament would say differently, particularly Paul. I go two places in Paul's letters for this answer, Galatians 3:16, 29, and Romans 9:6-9.
Galatians 3 deals fairly extensively with this issue, but these two verses seem to tie things together nicely. Christ is the seed of Abraham (3:16) and if we are "Jew, Greek, slave, free, male, or female"(3:28) in Christ then we are Abraham's seed, "heirs according to the promise"(29). Also in Romans 9, Paul says clearly that not all who "descended from Israel are Israel" but rather the children of the promise, who we saw in Galatians, are those of us in Christ. There would be much more in Scripture to interact with in regard to this subject, but these Scriptures seem very clear. I am not trying to make a statement against ethnic or religious Jews, but rather I want to be where Scripture is in who is really Abraham's seed.
Although this short writing only answers who Abraham's true seed is, hopefully we can start thinking through more clearly what if looks like to be a Christian. Other places in Scripture speak of Christ declaring all foods clean (Mark 7:19), of not allowing others to judge you according to "holy" days (Col 2:16), and the book of Galatians is Paul's response to the new believers there turning to a different gospel, a gospel of Jesus plus law. So does being a Christian look like being a Jew of the Old Covenant? I think not. Actually a Christian may look very different from culture to culture, yet always having the bond of the Spirit with other believers and a life marked (however imperfectly) by a pursuit of knowing Christ more fully. We are in such a good place living on this side of the cross and the completion of God's special revelation, that we can see the progress of God's redemptive plan fulfilled in His church!