It’s hard to tell where to start with all the things wrong with what you’ve said:

1. Palestinians include people of multiple religions.
2. Muslims do not believe they are God’s “chosen ones”
3. Neither does Islam have any concept of birthrights based on religion.
4. Palestinian claims to Jerusalem (and Palestine in general) aren’t based on religion but rather the fact that it actually is their land.

It’s sounds like you’ve been taken in by Israeli propaganda that tries to misrepresent the root causes.

The real root cause is colonialism. It’s not about religion at all except as an excuse to colonize the region.