Israel is the owner of Gaza. Israel won the Gaza strip by winning the 1967 war with Egypt in the 6 day war. That's what happens in war. In this case, Egypt attempted to destroy Israel and lost the war. The product of losing is losing your land. "Occupation" is a bogus word used by losers. If you don't want to lose your land and country, then don't pick a war and lose. And, because of the losses, including in 1972, they lost the West Bank. Israel always has owned East Jerusalem.
Isaiah 54:1-13 says in the last days Israel will extend its boarders on all sides and get back the land that other nations occupied. An obvious vision of the future except to Muslims like yourself.