As the most famous verse in the New Testament goes, “For God so loved the world that he gave his only begotten Son, that whoever believes in him should not perish, but have eternal life” (John 3:16). The Greek term for “only begotten” is μονογενής (monogenés), a compound word that the above translation assumes is made up of μόνος (translated “only”) and γίνομαι (“to become”). Two issues arise with the rendering of μονογενής as “only begotten.” First, according to the prologue of John’s Gospel, God does not “beget” the Son; rather, the divine being who would become incarnate in Jesus is coexistent with the Father: “In the beginning was the Word, and the Word was with God and the Word was God. He was in the beginning with God” (John 1:1-2). Second, Israel’s Scriptures describe God having more than one “son,” so Jesus being the “only” Son runs counter to previous biblical witness. Instead of translating μονογενής as “only begotten,” it is more theologically accurate to understand Jesus as the “one-of-a-kind” or “unique” Son of God.
The first half of μονογενής (from monos) can mean “only,” but it can also mean “one”—as in “monotheism,” the belief in the existence of one God. Based on the assumption that μονογενής derives from the verb γίνομαι (“to become”), traditional English translations speak of Jesus as the “only begotten” of God. However, the latter part of monogenés comes from the Greek word γένος (génos)—hence the Latin, biological term genus—which means a “kind” or “species.” Therefore, a more literal rendering of μονογενής is “one of a kind.”
The notion that Jesus is the “one-of-a-kind” Son, rather than the “only begotten,” makes much better sense of the biblical data. According to Israel’s Scriptures, God has many “sons.” For instance, the heavenly “sons of God” (בני האלהים; benei ha’elohim) notice the “daughters of humanity” (בנות האדם; benot ha’adam) and produce the Nephilim in the days of Noah (Genesis 6:2-4). Moses declares that God divided national borders based on the “number of the sons of God” available to govern the non-Israelite nations (Deuteronomy 32:8). These same “sons of God” appear before the Lord in the divine council according to Job’s prologue (Job 1:6; 2:1) and exist in the heavens prior to earthly creation (Job 38:7). The psalmist asks, “For who in the clouds can be compared to the Lord? Who is like the Lord among the sons of God (בני אלים; benei elim), a God greatly to be feared in the council of the holy ones, and awesome above all who are around him?” (Psalm 89:6-7). The psalm clarifies that while no one is like God in terms of greatness and exaltation—which is why the Lord is called the “Most High God” (אל אליון; el elyon) throughout Scripture—other “sons of God” exist in the heavenly realm.
The New Testament alludes to the fact that μονογενής means “one of a kind,” rather than “only begotten.” The letter to the Hebrews states, “By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises was in the act of offering up his monogenés” (Heb 11:17). Though most English translations say that the patriarch nearly sacrificed his “only” son, his “one and only,” or his “only begotten son” (cf. CEB, ESV, KJV, NASB, NIV, NRSV), every Bible reader knows that Isaac was not Abraham’s only son. However, Isaac was his father’s “one-of-a-kind” son insofar as Sarah’s offspring was the conduit of God’s “continual covenant” with the people of Israel (Genesis 17:19; cf. Romans 9:7-9). As the Word made flesh, Jesus is God’s unique Son—one who is both with God and is God. All the other heavenly children of God are subordinate to the Most High, whereas the Monogenés of the Lord is coexistent and coterminous with God. As celebrations of Jesus’ birth approach, Advent anticipates the arrival of the one-of-a-kind Son from the Father who is set apart in glory above all other sons of God.