Their clergies. They convince those they teach the other side is full of godless people deserving to be killed. Each group of clergy make their deals with the governments to deliver men to fight for them in exchange for money and power. Their followers are simply used to obeying what they are told as truth.
In reality, members of the same faiths are on the other side as well. Their clergies are telling them the same thing for the same reasons. So they play both sides against each other. The only winners are the clergies and one political power that beats the other. Have you noticed how little regard for those in their care, the clergies have?
Just as the Pharisees attitude was the Pharisees dismissed poor, common people with the contemptuous term ʽam-ha‧ʼa′rets, or “people of the land.” They used the people to get the best seats at the best tables of the city among the rich and famous. Things have really not changed.
-Anonymous