Christian Zionism is a way of thinking that some Christians have that believes that the nation of Israel (the country in the Middle East) should always be the top priority for Christians, and that God will reward them if they follow this way of thinking. This includes things like supporting Israel's government and military, and trying to help people who live in Israel. It's called "Zionism" because the idea comes from the Bible, which says that someday God will bring all of his people to the city of Zion (which is another word for Jerusalem, the capital of Israel).