When the Gospels and the New Testament letters were being written some 150 years after the LXX had been completed, the LXX had by then become entrenched and widely circulated in the Greek-speaking world. Greek itself had become the lingua franca or universal language of the Roman world, especially in commerce, much as English has become the language of international commerce today. That is why Paul and the other New Testament writers would usually cite Old Testament passages not from the original Hebrew Bible but from the LXX, the most important Greek translation of the Hebrew. It is only natural for the New Testament, which has come to us in Greek, to cite Scripture from the Greek LXX