According to the available evidence not many pagans knew the Greek Bible (Septuagint) before the advent of Christianity. Those pagans who later became aware of Christian texts were among the first, according to the surviving data, to seriously explore the Septuagint. They found the Bible to be difficult reading. The pagans who reacted to biblical texts include Celsus (II C.E.), Porphyry (III C.E.), and Julian the Apostate (IV C.E.). These authors thought that if they could refute one of the primary foundations of Christianity, namely its use or interpretation of the Septuagint, then the new religion would perhaps crumble. John Granger Cook analyzes these pagans' voice and elaborates on its importance, since it shows how Septuagint texts appeared in the eyes of Greco-Roman intellectuals. Theirs was not an abstract interest, however, because they knew that Christianity posed a grave danger to some of their dearest beliefs, self-understanding, and way of life.