It was never actually Palastinian land. It was Jewish land, then Roman land, then Ottoman land, then British land, then Jewish land after Palastinians attacked Israel and lost. At no point were the Palastinians ever a sovereign country and in fact they incredibly foolishly rejected the UN offer for one.
"other creeds and ethnicities should be second class "
Approximately 2.5 to 2.6 million non-Jews live in Israel, comprising about 25% to 26% of the country's total population. This is compared to less than 1% of the population of Gaza being non-muslim.