Since the title “Only Begotten Son” implies that the Son of God had a beginning, it has proven to be a dilemma for Trinitarians. Many Trinitarians, aware of the weakness of modifying “only begotten son” to mean eternally generated by the Father, have used another approach. They claim the Greek word monogenes, when applied to the Son of God, means the only one of a class or kind instead of only begotten. Hence, they refer to Jesus as the “only Son,” not “only begotten Son.”

Kittel’s THEOLOGICAL DICTlONARY OF THE NEW TESTAMENT (Vol. 5, pp. 738-741) 1967, a staunch Trinitarian work, observes that monogenes can have a broader meaning than only begotten. However, it goes on to state that when monogenes is used in the New Testament,

It means ‘only begotten’. In (John) 3:16, 18; 1 John 4:9; (John) 1:18 the relation of Jesus is not just compared to that of an only child to its father. It is the relation of the only begotten to the father. In John 1:14, 18; 3:16, 18; 1 John 4:9 monogenes denotes more than the uniqueness or incomparability of Jesus. In all these verses He is expressly called the Son, and He is regarded as such in 1:14. In John monogenes denotes the origin of Jesus. He is monogenes as the only begotten.

In addition to the five foregoing citations in which “only begotten” refers to Jesus, monogenes is used four other times (Luke 7:ll, 12; 8:41, 42; 9:38; Heb. 11:17-18). These four instances confirm Kittel’s observation that in New Testament usage, monogenes solely denotes an only begotten son or daughter.

John 1:18 points up a further difficulty of monogenes for Trinitarians. According to some of the oldest and best manuscripts (Example: Sinaitic Codex and Vatican Codex l209), the phrase “only begotten Son” should read “only begotten God.” Most scholars recognize the superiority of this reading. Therefore, John 1:18 reads: “No man hath seen God at any time; the only begotten God, which is in the bosom of the Father, he hath declared him.” In harmony with John 1:1, our Lord Jesus Christ is a god separate and distinct from the heavenly Father. Further, he had a beginning. He is the “only begotten god.” The heavenly Father alone was without beginning.

To circumvent this scriptural logic, some Trinitarians arbitrarily change the phrase “only begotten God” to “God only begotten.” But as the Trinitarian W. J. Hickie, in his Greek- English Lexicon to the New Testament (1963 edition) observes,

It is hard to see why monogenes huios must be translated “the only begotten Son,” while monogenes theos, which is given by Westcott and Tregelles after the very oldest MSS, must not be translated the only begotten god, but god only begotten.

From the foregoing, it is clear that monogenes, when used with the Son of God, denotes the Only Begotten Son, who had a beginning. And this nullifies the concept of three Gods, co-eternal, without beginning.