Only the title “Christ” rivals the popularity of Jesus’ epithet “son of God.” Christianity did not invent the concept of “sonship of God” but inherited it from Judaism. However, Christianity changed this concept fundamentally by extending its meaning to imply divine qualities — something it never had in Judaism.
The title “son of God” is used in the Old Testament in four distinct ways:
(1) It is used for unidentified non-human beings:
When man began to multiply on the face of the land and daughters were born to them, the sons of God saw that the daughters of man were attractive. And they took as their wives any they chose. Then the Lord said, “My Spirit shall not abide in man forever, for he is flesh: his days shall be 120 years.” The Nephilim were on the earth in those days, and also afterward, when the sons of God came in to the daughters of man and they bore children to them. These were the mighty men who were of old, the men of renown. (Gen. 6:1-4)
The same Hebrew expression, beney ha’elohim, is found again only in the Book of Job where it is used for angels, suggesting that they are the unidentified non-human creatures of Genesis (also Job 2:1, 38:7):
Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them. (Job 1:6)
A very similar Hebrew expression with the same meaning, beney ‘elim, in the Book of Psalms (29:1, 89:6) also denotes angelic beings.
(2) King David is described as the “son of God” and God is called his father. Speaking to the Prophet Nathan, God said about David: “I will be to him a father, and he shall be to me a son” (2 Sam. 7:14). In one of the Psalms, the king says: “I will tell of the decree: The Lord said to me, ‘You are my Son; today I have begotten you’” (Ps. 2:7).
(3) All of Israel is described as God’s son (Hos. 11:1). This is part of God’s instructions to Moses:
Then you shall say to Pharaoh, “Thus says the Lord, Israel is my firstborn son, and I say to you, ‘Let my son go that he may serve me.’ If you refuse to let him go, behold, I will kill your firstborn son.” (Exo. 4:22-23)
(4) In post-Biblical periods the title “son of God” started to be applied only to pious Jews, as in the following passage from the apocryphal Book of Jubilees, which is dated from the middle of the 2nd century BCE:
And the Lord said to Moses: “I know their contrariness and their thoughts and their stiffneckedness, and they will not be obedient until they confess their own sin and the sin of their fathers. And after this they will turn to Me in all uprightness and with all (their) heart and with all (their) soul, and I will circumcise the foreskin of their heart and the foreskin of the heart of their seed, and I will create in them a holy spirit, and I will cleanse them so that they shall not turn away from Me from that day unto eternity. And their souls will cleave to Me and to all My commandments, and they will fulfil My commandments, and I will be their Father and they shall be My children. And they all shall be called children of the living God, and every angel and every spirit shall know, yes, they shall know that these are My children, and that I am their Father in uprightness and righteousness, and that I love them.” (Jub. 1:21-24)
According to the 1st century BCE Book of the Psalms of Solomon, the Messiah will purify the Jews, who will then become “sons of their God”:
And he shall gather together a holy people, whom he shall lead in righteousness,
And he shall judge the tribes of the people that has been sanctified by the Lord his God.
And he shall not suffer unrighteousness to lodge any more in their midst,
Nor shall there dwell with them any man that knows wickedness,
For he shall know them, that they are all sons of their God.
And he shall divide them according to their tribes upon the land,
And neither sojourner nor alien shall sojourn with them anymore. (PsSol. 17)
Vermes (2000: 32) suggests that in the 2nd century BCE, the title “son of God” started to be applied to the awaited royal Messiah, but other scholars contend that this was never a title of the Messiah (Miller, 2003: 224).
In all four Jewish uses, the title “son of God” is always used as a figure of speech. A son of God is someone who is close to God, but he does not share the divinity of God. Sonship of God does not mean that the person is divine, even when applied to individuals who are deemed to be particularly close to God. The Talmud states that two renowned Jewish miracle workers were called sons of God. One of these was Honi, who lived around the middle of the 1st century BCE and developed fame for successfully praying for rain by drawing a magical circle. In one prayer, in which he calls himself a member of God’s house, Honi calls the Jews God’s children:
Master of the Universe, Thy children have turned to me because [they believe] me to be a member of Thy house. I swear by Thy great name that I will not move from here until you have mercy upon Thy children! (Ta’an. 23a)
The second miracle worker is the healer Hanina ben Dosa who lived in the 1st century CE, about one generation after Jesus. Hanina is reported to have performed many miracles, some similar to Jesus’. One Talmudic account claims that a divine voice used to call Hanina “My son” (Bera. 17b):
Rab Judah said in the name of Rab: Every day a Heavenly Voice is heard declaring, the whole world draws its sustenance because [of the merit] of Hanina my son, and Hanina my son suffices himself with a kab of carobs from one Sabbath eve to another. (Ta’an. 24b)
This sonship of God did not mean to the Rabbi writers of the Talmud or to its Jewish readers that Honi or Hanina had any divine attributes or were more than human beings. They were merely considered to be close to God and that nearness is seen as the cause of their abilities to perform miracles. This nearness to God is different from the concept sonship of God in Roman polytheistic religions where it denoted divinity. Judaism restricted divinity to God. This is the main difference between the Jewish use of the title “son of God” and its use in Christianity. So while it is true that Christianity did not invent the concept of sonship of God but inherited it from Judaism, it developed it to something completely different from its Jewish origin.