If I'd done a better job on that post, I'd have mentioned that Wellum is deconstructing Covenant Theology, in the process of demonstrating that paedobaptism is grounded in a misunderstanding of the relationship between the biblical covenants. He spends the first 28 pages of this 65-page chapter simply unpacking the covenantal argument for infant baptism. Yesterday's post didn't summarize that argument, but it emerged from that portion. If you want a summary, it's in the PDF.
This post emerges from the second portion of Wellum's chapter, which is an evaluation and critique of the covenantal argument for infant baptism. Though, my purpose for this post and the whole series is less about our conclusions on baptism, and more about the significant issues further upstream—the relationships among the biblical covenants.
So on that note, one of the conversations that's come up here from time to time is the Abrahamic Covenant and the identity of Abraham's "seed" or "offspring" in relationship to the promises of the Abrahamic Covenant. It's essential that we get the seed right if we're going to get the Bible right. As it happens, I've been reading John Reisinger's "Abraham's Four Seeds," which Wellum helpfully summarizes in his chapter.
I've found Wellum's overall argument and critique to be tighter and more on-point than Reisinger's, though Reisinger is certainly helpful. Here's Wellum's survey of the data on the four biblical senses of Abraham's "seed":
My answer is no. We see this by answering the important question, Who is the seed of Abraham? Who is the true heir of God’s promise? Scripture teaches that there are four senses that must be distinguished and not confused. Let us look at each of these in turn.Brief note: I've removed the footnotes, though they're obviously available in the PDF and print editions. There's also a discrepancy between the pagination of the PDF and the print edition. This extended quote is on pages 133-135 of my book, but pages 141-144 in the PDF. I haven't figured out how to account for the difference.
1. The “seed of Abraham” ﬁrst refers to a natural (physical) seed, namely, every person who was in any way physically descended from Abraham such as Ishmael, Isaac, the sons of Keturah, and
by extension Esau, Jacob, etc. In each case, all of these children of Abraham received circumcision even though many of them were unbelievers, and even though it was only through one of the “seeds,” Isaac, that God’s promises and covenant was realized (Gen 17:20–21; cp. Rom 9:6–9). Circumcision also marked out those who were not physically Abraham’s descendants, but who were related to him either through a household birth or purchased as a slave (Gen 17:12). In the latter case, circumcision enabled those who were not biologically related to Abraham to become his children and thus beneﬁ t from the divine blessing mediated through him.
2. The “seed of Abraham” also refers to a natural, yet special seed tied to God’s elective and saving purposes, namely Isaac, and by extension Jacob and the entire nation of Israel. As God enters into covenant relationship with Israel, they are a special, chosen people (Deut 7:7–10). As in the case of the natural seed, they too are marked as Abraham’s seed by circumcision. But as a nation, they are a “mixed” entity comprising believers and unbelievers—Elijahs and Ahabs simultaneously—even though all males within the covenant nation, regardless of whether they were spiritually regenerate, were marked by the covenant sign of circumcision. In fact, being God’s chosen people did not guarantee that they would receive God’s ultimate redemptive blessings (see Matt 3:9; Luke 3:8; 16:19–31; John 8:31–39; Rom 9:1–15). Instead, their being marked with the covenant sign not only showed their relationship to Abraham, but also, unlike the mere natural seed (Ishmael), allowed them the supreme privilege of bringing God’s blessing to all nations through the coming of the Messiah.
3. The Messiah is the third sense of the “seed of Abraham.” In Gal 3:16, Paul argues that the singular use of “seed” in Gen 12:3 and other places is a reference to the true/unique “seed of Abraham,” namely Christ. Here Paul is picking up the promise theme from Gen 3:15, traced through a distinctive line of seed, beginning with Adam, running through Noah, Abraham, Isaac, Israel, David, and eventually culminating in Christ. In Christ, we have the promised seed, the mediator of God’s people, the one who fulﬁlls all God’s promises, not least the Abrahamic promises. Hence, he is the true seed of Abraham, the true Israel, and David’s greater Son. In this important sense, then, Jesus is the unique seed of Abraham both as a physical seed through a speciﬁc genealogical line and as the antitype of all the covenant mediators of the OT. What is crucial to note at this juncture is how in Christ, viewed as the true seed of Abraham and the mediatorial head of the new covenant, there is a signiﬁcant typological advance as we move across the covenants which has implications for understanding the expression “to you and your seed.” This is clear in the fourth sense of the “seed of Abraham.”
4. In this last sense of the “seed of Abraham,” the NT emphasizes its spiritual nature now that Christ has come. It includes within it both believing Jews and Gentiles in the church. Given the new era that Christ has inaugurated, the way into Abraham’s family is not dependent on circumcision or the Torah, but it comes through faith and spiritual rebirth. Only those who have experienced conversion are those who are Abraham’s “seed” in this spiritual sense. To be a member of Abraham’s family now is not tied to a speciﬁc physical lineage, nor circumcision, nor any kind of physical links to other believers. Rather, one becomes a part of Abraham’s family only through faith union in Christ brought about by the Spirit (Gal 3:26–29). Thus, in the coming of Christ, a new era of redemptive history has dawned where the structures, types, and shadows of the old have given way to the reality and fulﬁllment of what the OT was all along pointing to.