How do Jewish people justify their treatment of the Palestinians? How do they tell themselves that it's OK to rob people of their land and kick them out and then say that you were morally just in doing so and that they're the terrorists for resisting? .
It's pretty straightforward, I'll start with the most important.
1. 60%, A MAJORITY of Jews in Israel, are descendant of Jews who had already been living in the middle east for literal milenia prior to the founding of Israel, and were driven to drop everything, abandon their property, and flee to the not-yet-official Jewish state in order to escape ethnic cleansing by Arab muslims. These large scale cleansings were in major part inspired by the Nazis.
2. Arab states announced their intention to invade Israel and kill its entire Jewish population BEFORE the large scale expulsion of the Palestinian population had actually happened. In other words, the nakhba, the very event that the Arab states cite as justification for their attempted genocide, did not actually happen until they had already openly declared that genocidal intent. I will leave the implication for you to draw.
3. Many Arab leaders openly praised the third Reich and went out of their way to establish good relations. This includes sending volunteer fighters to fight in the SS once the Germans started accepting foreign volunteers late in the war to make up for a lack of their own, and there was no shortage of Arab volunteers. Additionally, Arab officers cooperated and trained under Nazi officers as part of a military education program for the fledgling Arab states, and many of these officers would become the generals who lead the Arab armies against Israel in the first three Arab invasion attempts.
3. Arab muslims built a mosque on top of the holiest place in Judaism and claim it has having always been theirs, and any Jewish attempts at greater control as an unacceptable encroachment. This is despite the first temple having been built over 1000 years before al aqsa, and the fact that the IDF wanted to destroy it during the first Arab Israeli war but was ordered not to by Israeli leadership.
4. If you read the Quran, it is very clear that Jews are explicitly viewed as an especially evil and inferior ethnicity from the standpoint of Muhammad, and there are several passages that call for their total extermination. Arab states have always just tolerated Jews at best, with them often turning a blind eye to periodic pogroms and massacres of the same kind as those experiences by Jews in eastern Europe.
5. The Palestinian side has flatly refused any kind of peace or land deal whatsoever, even relatively favorable ones like that offered at camp David where they would have been able to retain the whole of Gaza, the west bank, and east Jerusalem in exchange for peace.
5. Gaza was not always a living hell under blockade. Economic conditions were vastly better prior to Hamas rising to power, yet the population there chose to elect them anyway, despite warnings from the Israeli government that a blockade would be instated if they did. This blockade was instated because Hamas is an organization that has a very clearly stated intent to indiscriminately kill Israel's entire Jewish population in its founding charter.
6. Arabs accuse Israel of being a Jewish ethnostate even though 20% of its citizens are Arab Muslims with full civil rights.
