Why are translations in Greek instead of Hebrew, the language Jesus spoke in?

Answer:

The following is specific toward Matthew, which is usually the one book people like to claim was originally written in Hebrew: Was Matthew originally written in Hebrew or Aramaic?

The simple fact is that it was the Holy Spirit, who inspired the apostles and prophets of the New Testament to write in the Greek language. "These things we also speak, not in words which man's wisdom teaches but which the Holy Spirit teaches, comparing spiritual things with spiritual" (I Corinthians 2: 13). The evidence that the original documents were in Greek is large and varied. The earliest Hebrew copies of the New Testament date far later than the Greek copies and they are clearly translations from Greek.

It appears that Jesus probably spoke in Aramaic and switched to Hebrew as needed. These languages were of limited use in the world at large. To reach the wider audience of the Gentiles, as God declared He intended, the Greek language, which was widely known, was used as the "universal" language of that time. "Indeed He says, 'It is too small a thing that You should be My Servant To raise up the tribes of Jacob, And to restore the preserved ones of Israel; I will also give You as a light to the Gentiles, That You should be My salvation to the ends of the earth'" (Isaiah 49:6).