Were not Muslims, Christians, and Jews all living peacefully in Palestine during the Palestine mandate?

During the British had the mandate of Palestine, everyone was living together in peace. All were for serving the God of Abraham. Jews might have been persecuted and oppressed in Europe but that just wasn't the case in Palestine during that time. And the one's in Europe who were being oppressed and persecuted could have easily fled to Palestine without objection. They would have even opened them with open arms, I mean it was a country that believed in the God of Abraham afterall. It kinda was your land eventhough Israel wasn't an official state or country. Did declaring Israel an indepedant state in 1948, ruin what a good thing they had going?