Doctrinal devolution does not happen all at once. Rather, it is a slow process. There can be a certain order to it. When people shift away from a Christian worldview, they tend to first dispose of the idea that the Bible is entirely truthful—biblical inerrancy. From that position of rejecting biblical truth, it’s only a small step to other perverse beliefs like, “Premarital sex can’t be that bad.”
Biblical inerrancy functions like a “canary in a coal mine.” This idiom refers to a certain coal mining practice. Miners used to take caged canaries (small birds) into the coal mines. These birds are highly sensitive to harmful gases, more so than humans. If the canary died, that meant that dangerous gases were present, and so the miners would immediately exit the mine. The canary served as an early warning sign of imminent danger. That’s how biblical inerrancy functions. It’s a canary in the coal mine for Christian theology.
Paul tells Timothy in 1 Tim 4:16 to persist in keeping a close watch on his doctrine. Like Timothy, we too need to keep a close watch on our doctrine—specifically, on what we believe regarding the truthfulness of Scripture. It’s our canary in the coal mine. Keep it safe. Never let go of the conviction of the belief that the Bible is the very Word of God.