To me, a conflict about religion is when two sides are fighting because of a difference in religious beliefs. In this situation, they aren't mainly fighting about that. The issue is colonialism, inequality, and land. If Israel was a Muslim or Christian country but still acting the same, the conflict would still exist.
For instance, if Israel was created on land that was empty but happened to be in that area, the conflict would not exist. The current problem was created when Europeans decided to give an already populated land to someone else. That is the core problem. The religious differences became another layer in the conflict, and it plays a part, but is not the root cause, in my opinion.