Galatian4:4 says, "When the fullness of time came, God sent forth His Son, born of a woman, born under the Law.“ It speaks of God the Father's timing in transitioning the world from the age of the Mosaic Law to the age of adult sons in the family of God.
Yet it also remind us of the many historical factors that came together perfectly in preparation for Jesus' entrance onto the world stage.
The Hebrew scriptures provide inklings of God's special preparations for His Son. Abraham and his descendants were to live in a specific place, the "Promised Land" (Gen 12:1).
Amazingly, this land lies between the three great continents of Asia, Africa, and Europe. In fact, God calls Jerusalem the "center" of the earth: "Thus says the Lord God: 'This is Jerusalem; I have set her in the midst of the nations and the countries all around her'" (Eze 5:5).
The nations were arrayed around Israel so the Jewish nation could be a "kingdom of priests" (Ex 19:6) and represent God to the Gentile world (Deut 32:8). Almost all of the books of the Bible were authored by Jewish men. In the future, after God removes the true church from the earth through the Rapture, He will reignite Israel as His spiritual light (Rev 7, 11, 14).
As the Messiah's birth through a Jewish woman approached, we can imagine God the Father monitoring certain factors for peak ripeness:
(1) Adequate lapse of time for the Jewish people to appreciate the Law of Moses and for humanity to demonstrate its inability to obey that Law. This was the theological setting.
The books of Galatians and Hebrews specifically explain Jesus' superiority as a High Priest and the New Covenant's superiority over the Old. However, it would require centuries of laboring under the Law for people to understand these truths.
(2) A specific number of people on Earth. God the Father did not bring His Son into a world that contained a mere handful of humans. He waited until an impressive number could observe Christ's life, death, and resurrection. An estimated 300 million people inhabited the known world in Christ's day.
Amazingly, Jewish people constituted about 1 percent of that total, with about 50,000 Jewish individuals living in Jerusalem. That is a far different ratio from what exists today, with a mere 15 million Jewish people in a world population of 7 billion.
(3) Adequate development of languages capable of explaining legal and abstract principles and the rise of one accepted language of international communication.
We need look no further than the inscription over Christ's cross to realize the significance of the precise Greek and Latin languages: "Now Pilate wrote a title and put it on the cross. And the writing was: JESUS OF NAZARETH, THE KING OF THE JEWS...And it was written in Hebrew (some...translations say Aramaic), Greek, and Latin" (Jn 19:19-20).
Latin was the legal language of the executing authority. Greek was the international language, used to be sure all could read and heed. Aramaic was the local language to ensure those most likely to rebel would understand the consequences.