We are not here to discuss religious matters. There is another section on this forum where beliefs are discussed, their nuances, correlation with the modern time etc. Torah also says about stoning as a punishment. Some Jewish religious groups say that Torah directly forbids the state of Israel as it was created 70 years ago. So, let's just stop here with that.
It does not matter whether there was such nation as 'Palestine' or not. Some time ago, in not too distant past, there were not such nation as 'Americans', many East European and Asian nations etc. People who apply this way of reasoning are more fit for a kindergarten's playground than a political board.
There was the Arabs there. Is their centuries long history in that region enough to say they 'were' there? You can call them Palestinians or Gazans or Jordanians or Arabs, that doesn't change a thing.
When all this story started, this land was supposed to be divided in two parts - Jewish state and Arab/Muslim state. Yes, the Arabs rejected this plan, and they won't have their state with proposed 1948 borders. It is quite likely, they won't have the 1967 borders, either.
But if your plan is to expel them or 'push them to the sea', then be ready for the entire Middle East turning into 'Hamas'.