It is undeniable that the genealogical lists in Scripture can seem boring. But, rightly understood, they do have both a narrative and a covenantal significance in several ways.
Narratively, they give a sense of time, space, and relational context. The Genesis 5 genealogy, for example, describes the growth of human families, whereas the Genesis 10 genealogy takes this further to show the emergence and spread of nations. In doing this, they also make important theological points and provide focus and direction to the biblical narrative. The lists in Genesis 5 put forth the unusually long lifetimes of the prediluvian patriarchs, thereby making the theological point that man as originally constituted was intended to live much longer than is the case now, and what seems to us to be normal is really a result of the Fall. That stretches our imagination beyond its existing horizon to think of a world that once was and now is no more. In addition, the genealogies act as a kind of dramatis personae in the biblical narrative, listing out the characters and providing background information that will be useful later in the narrative to understand the relationships of the individuals and peoples to one another. This is often seen like a camera zooming in on a key character. The Genesis 11 genealogy does this by zeroing in on Abraham’s family, through whom God’s covenant grace will come, and similarly Matthew 1 connects the Old Testament narrative to Christ.
Covenantally, the genealogies demonstrate three things. First, they show God’s providential ordering of the peoples. In the ancient world, kings would have to grapple with the various degrees of familial relations in order to manage relationships and conflict, adjudicating claims between different vassals on matters such as inheritance and legitimacy. Second, they could establish the legitimacy to power of kings themselves. Christ’s genealogy in Matthew 1, for example, establishes His legal connection as a son of David, which was integral to His claim to be Messiah. Lastly, they often are reminders to God’s redemptive work. This can be best seen in the Matthew 1 genealogy recounting Jesus’s lineage. The genealogical narrative there is divided chronologically into the periods between Abraham and David, between David and the Exile, and between the Exile and Christ (Matt. 1:17). This captures the arc of the Covenant of Grace. The Covenant of Grace is seminally rooted in God’s Old Covenant promises to Abraham (Gen. 15, 17, and 22), reaches a particular high point in promising the coming of the Messiah in God’s covenant with David (2 Sam. 7) and find its culmination with the New Covenant fulfillment in Christ Jesus. If one knows the Old Testament, then in just sixteen verses one can get the entire narrative arc of biblical redemptive history just by remembering what the different figures did.