The first way to answer this question is historically.  The reason the apostles wrote their New Testament books in Greek is that Greek was the dominant language, the lingua franca, of the world in which they lived.  Prior to the 4th century B.C., Aramaic was the dominant language of the Mediterranean world, reflecting the long dominance of the Mesopotamian empires.  But during the Golden Age of Greece, and especially as a result of the sweeping conquests of Alexander the Great, the Greek language increasingly dominated the international life of the ancient world.  The Roman Empire, which overthrew the Greek powers, was known for its military and political superiority, and adapted the higher culture of Greece.  Latin became the language of empire, while Greek remained the language of literature and philosophy.

Because of all this, the Israel of Jesus’ day was multilingual as well as multi-cultural.  One measure of the declining spirituality of the Jewish people is that their own language, and the language of the Old Testament, Hebrew, became increasingly separated from the life of the people.  The common language of the people was Aramaic, and apart from the Jewish elite and scholars like the Pharisees and scribes, few Jews could either read or write Hebrew.  This was especially true outside of Palestine.  Around 200 B.C., the important Jewish community in Alexandria, Egypt produced the Greek translation of the Old Testament known as the Septuagint.  In Jesus’ day this was the most familiar version of the Old Testament among the Jewish people.  Without doubt, Jesus would have spoken Aramaic, Greek, and Hebrew, and the familiarity of those languages among the people would have been in that same order. Theologically, why might God have arranged for Greek to become the language that would present the message of Jesus Christ and his gospel to the world?  I can think of three reasons.

First, the Greek language had been molded over the centuries by the categories of philosophical thought.  This is what Greece is known for, and their language had well-developed truth categories that would be needed to convey the doctrines of Christianity.  To read the New Testament in Greek is to realize how perfect that language is for the theological writings of apostles like Paul and John.

Second, unlike the Hebrew Old Testament, the Greek New Testament was recorded in a language that was truly universal.  One of the strongest factors in the growth of the Christian church was that its key sacred writings were propagated in the common tongue.  The availability of a language like Greek, which had by then been spread around the ancient world for at least a couple of centuries, was greatly used by God in the missionary work of the church.
Third, the apostles’ use of Greek helped to unify the church.  Had the New Testament been written in Hebrew, the church would likely have been dominated by the Judaizers in such a way as to make the Gentile converts second-class members.  But with the Gentiles’ language as that of the apostles, it was that much harder to thwart the unity of the early church.

Let me conclude by asking, is it a problem for you not to be able to read the Greek New Testament, that is, the actual words of the apostles?  I would certainly encourage any believer so motivated to learn Greek, but you can be confident in the many excellent English translations, which God uses to convey his Word in a reliable fashion today.

Rev. Richard Phillips is the chair of the Philadelphia Conference on Reformed Theology and senior pastor at First Presbyterian Church Coral Springs, Margate, Florida