Answer:
Both of this Empires incorporated much of the known world, which allowed information and knowledge to be spread faster than ever before. This enabled of course the spreading of word of coming of God's son to Earth. On the other side, this Empires failed to satisfy the need of common people who believed in the coming of the chosen one.
Step-by-step explanation:
Large empires such as this enabled that certain ideas spread faster. Prophecies of different kind, including the one about Jesus Christ were spreading across this empires, which led to people believing in his coming. These empires were polytheistic and they forbade the belief in one God, which provoked monotheistic believers further more.