But many Zionists weren't, and aren't, religious
For many Israel isn't so much an issue of Jewish religion as it is Jewish history and culture, and a reconnection with the land of their ancestors.
Many of the founders of Israel were socialists and secular. The first Jewish settlers in newly captured territory after 1967 were secular, not religious. The religious nutcases didn't come and build their settlements until later.
Even today the Russian Jewish immigrants to Israel are very strong Zionists - but many don't even believe in God.
Sure, there are lots of religious idiots in Israel, but not even a small fraction of the number of Islamic lunatics trying to destroy Israel.