Just before telling us about the tower of Babel, Genesis provides Shem’s genealogy.  Just after the tower of Babel, Shem’s lineage is repeated.  Why?  There is an important difference in the way Shem’s lineage is stated the second time.  Here’s a sample: 

“These are the family records of Shem.  Shem lived 100 years and fathered Arpachshad two years after the flood.  After he fathered Arpachshad, Shem lived 500 years and fathered other sons and daughters.  Arpachshad lived 35 years and fathered Shelah. After he fathered Shelah, Arpachshad lived 403 years and fathered other sons and daughters” (Gen. 11:10-13).  

Shem’s second genealogy only names one son each generation.  That other sons and daughters were born is acknowledged but none of them are named.  The first time we read Shem’s genealogy, other descendents are named.  Shem’s first genealogy also follows Japheth’s and Ham’s; we learn how all the nations fanned out from these brothers. The second genealogy stands alone and brings us from Shem to Abram; it is only concerned with one family.

With Shem’s second genealogy, Genesis starts to focus on the promised seed.  Only the ancestors of that seed are named.  This society of the seed is almost given in contrast to the society of Babel.  Babel was a society based on what security could be found in concrete, an imposing tower, a fearsome reputation.  The society of the seed was based on something not concrete—a promise.  To us, a promise seems as insubstantial as the breath that utters it.

God’s promise was of a seed or offspring (Gen. 15:4-5).  This perhaps hearkened back to His first promise in Genesis—the seed of the woman would crush the head of the serpent (Gen. 3:15).  Isaac was the immediate fulfillment of this promise (Gal. 4:23).  Spiritually, the promise was of another seed, “who is Christ” (Gal. 3:16).  Christ crushed the head of the serpent at the cross and rose as Heir to all God prepared for humanity.

The way Shem’s second genealogy is presented signals a focus on Christ, God’s seed.  Seed, of course, implies image since someone’s seed carries on their family resemblance.  Hebrews says, “The Son is the radiance of God’s glory and the exact expression of His nature” (Heb. 1:3).  The phrase “exact expression of His nature” is more literally translated “an engraving of His substance.”  So the Son is an engraving of the Father’s substance, the perfect image of God.

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Now the promises were spoken to Abraham and to his seed.  He does not say, “and to seeds,” as though referring to many, but referring to one, and to your seed, who is Christ. […]  For as many of you as have been baptized into Christ have put on Christ like a garment.  There is no Jew or Greek, slave or free, male or female; for you are all one in Christ Jesus.  And if you belong to Christ, then you are Abraham’s seed, heirs according to the promise (Gal. 3:16, 27-29).  

Christ, the seed, came from Abraham’s own body and was his heir.  If we belong to Christ, Paul says we are Abraham’s seed and heirs of God’s promise.  It is easy, in the 13 verses between 16 and 29, to begin thinking individually; that each of us in the church is a seed and heir.  But Paul has just told us, “He does not say, ‘and to seeds,’ as though referring to many, but referring to one…who is Christ” (Gal. 3:16).  

There is only one seed; we have been baptized, immersed in Him, and have put Him on like a garment.  Whatever we were in the flesh–Greek, Jew, slave, free, etc–we are no more.  Now we are One–Christ.    

It is not another Christ that is in us.  We do not have our own separate Christ.  There is only One Christ, Abraham’s seed and heir.  We are in the One, and the One is in us–the same substance, the same quality, the same Jesus.  The only Jesus.  Him and no other–now our life, our self, our totality.