Not all evangelical Christians are like this. There are two main branches: covenantal and dispensational. Dispensational theology is basically the same thing as Christian Zionism, and was invented in the 1800s by John Darby and his followers[1]. Covenantal theology goes way further back and is still popular today. For example Presbyterians are a major covenantal denomination.

[1] https://aish.com/unlikely-zionists-the-fascinating-story-of-...