That is an excellent question! Let’s read Galatians 4:4-5: “But when the fullness of time had come, God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons” (NKJV). The words “fullness of time” imply that God had ordained certain things to be accomplished and once they were, He would send His Son. So perhaps we could answer your question by listing two of those things that had to be accomplished.

  1. Daniel’s “Seventy Weeks prophecy” was running its course and the time had come for the Messiah to be revealed and rejected. God had given Daniel a timeline showing when Israel’s Messiah would come and be crucified. Daniel 9:25-26 reads, “So you are to know and discern that from the issuing of a decree to restore and rebuild Jerusalem until Messiah the Prince there will be seven weeks and sixty-two weeks; it will be built again, with plaza and moat, even in times of distress. Then after the sixty-two weeks the Messiah will be cut off and have nothing” (NASB). From the time that Jerusalem began to be rebuilt in the days of Nehemiah to the Messiah being “cut off in death,” there would be 69 weeks of years (which is 463 years). So, there was an exact date that God had picked for His Son to be crucified in order to provide redemption for guilty sinners and thus He sent His Son to fulfill the prophecy of Daniel.
  2. The Law had to serve its purpose. The Law was given to Israel to TEST MANKIND and when the test was over God sent forth His Son. God had actually been testing man from the beginning of his creation. He tested him in the Garden of Eden when he was still innocent, but he failed the test by eating the forbidden fruit (see Genesis 2:15-17; 3:1-6). He tested him from Adam to Noah but man’s conscience failed to guide him into holiness. Violence and corruption filled the earth and God decided to destroy the earth with a flood (see Genesis 6:1-13). He tested man by establishing government when Noah stepped off the Ark (Genesis 9:1-7) but in time the world became so wicked (by worshipping idols) that He chose Abraham to start a new race of people, the Israelites. To them He gave the FINAL TEST, which was the Law. Yet they too failed to obey God’s commandments, as we see from every other book in the Old Testament. In Romans 3:9-18 God lists the sinful condition of mankind during the time of the Law (which lasted 1500 years). Then His final verdict is given in verse 19: “Now we know that whatever the law says, it says to those who are under the law, that every mouth may be stopped, and all the world may become guilty before God.” Israel FAILED THE TEST! This proved that they were unable to live up to God’s standard of righteousness. God had used Israel as a sample of the human race to show that in truth the whole world was “guilty before God.” Now was the time for God to send His Son, for the whole world needed a Savior.

We could list other things that were accomplished in order to pave the way for God to send His Son. In God’s sovereignty He allowed the Roman Empire to make good roads and to establish a universal language (i.e. Greek) so that the gospel could be spread throughout the world after Christ died and rose again. But the two things listed above are the major accomplishments that would allow God to send His Son. Truly “the fullness of time had come.” (249.1) (DO)