Before I play wiffle ball in the back yard with my sons, we have to set the bases down so that we know what the playing field is. The first and third base line enable us to see when a batted ball is fair or foul.
Biblical theology has these, too.
Here’s the first base line: the Bible is true. Here’s the third base line: you can’t neglect or nullify any part of the Bible’s teaching. This means that no part of the evidence can be fudged. You can’t make the Bible mean the opposite of what it says. Foul ball. It also means that no part of the Bible can be ignored just because you don’t like the way it looks. That ball is in fair territory, even if it’s difficult for you to field it. We play this game in fair territory.