[Mr. K]

So The Bible says both “Sons of God” and “Only begotten son”

so which is it? Did God have more than one son or not?

[SparkyBass]

Now you're getting into a discussion on the subject of the Divine Council which logically leads to your query!
Dr. Michael Heiser (drmsh.com) has studied it extensively and collected other studies on this. Here is a footnote from his book "The Unseen Realm" (just finished it):

"μονογενής 3439 is literally “one of a kind,” “only,” “unique” (unicus), not “only-begotten,” which would be μονογέννητος (unigenitus), and is common in the LXX in this sense (e.g. Judg 11:34, Ps 21 (22):21, 24 (25):16, Tob 3:15). It is similarly used in the NT of “only” sons and daughters (Lk 7:12, 8:42, 9:38), and is so applied in a special sense to Christ in Jn 1:14, 18, 3:16, 18, 1 Jn 4:9, where the emphasis is on the thought that, as the “only” Son of God, He has no equal and is able fully to reveal the Father. We cannot enter here into the doctrinal aspects of the word, or into a discussion on the sources, Orphic or Gnostic, from which John is sometimes supposed to have drawn his use of it, but reference may be made to the art. by Kattenbusch “Only Begotten” in Hastings’ DCG ii. p. 281f. where the relative literature is given. A few exx. of the title from non-Biblical sources will, however, be of interest. In an imprecatory tablet from Carthage of iii/A.D., Wünsch AF p. 1837, we find—ὁρκίζω σε τὸν θεὸν . . . τὸν μονογενῆ τὸν ἐξ αὑτοῦ ἀναφανέντα, where the editor cites the great magical Paris papyrus, 1585 εἰσάκουσόν μου ὁ εἷς μονογενής. With this may be compared P Leid Vv. 34 (iii/iv A.D.) (= II. p. 21) εὐχαριστῶ σοι κύριε ὅ[τι] μοι [ἔλυσεν] τὸ ἅγιον πνεῦμα, τὸ μονογενές, τὸ ζωόν. See also Vett. Val. p. 1132. An inscr. in memory of a certain Plutarchus, Kaibel 1464 (iii/iv A.D.) describes him as μουνογενής περ ἐὼν καὶ πατέρεσσι φίλος. And the word is apparently used as a proper name in C. and B. i. p. 115, No. 17 (Hierapolis) Φλαβιανὸς ὁ καὶ Μονογονις εὐχαριστῶ τῇ θεῷ, where Ramsay thinks that we should probably read Μονογένης or Μηνογένης. For the true reading in Jn 1:18 it is hardly necessary to refer to Hort’s classical discussion in Two Dissertations, p. 1ff. James Hope Moulton and George Milligan, The Vocabulary of the Greek Testament (London: Hodder and Stoughton, 1930), 416–417."

[SparkyBass]

what the heck? weird formatting from FR right now!

[SparkyBass]

direct link since FR is translating pasted text rather oddly!)... discussions to point is further down the page.