“The fundamental truths of the Gospel are landmarks to keep us safely within the boundaries set by God. Suppose your grandfather owned some property which at one time had been carefully surveyed. He was there when they set the stakes and could have paced it off blindfolded. But he never took the time to show anyone else the markings.
“Over the years, the markers rotted, were rooted up, or washed away. Now your grandfather has died and left the land to you. But a dishonest neighbor claims it is his, and as proof of ownership points to the burgeoning crop of corn he has planted. You discover the deed and land description have been lost. Since you do not really know the proper boundary lines yourself, how will you defend your case in court? You will probably end up losing your property because no one ever told you where it ends and your neighbor’s begins.
“The spiritual parallel is this: Every fundamental truth has some evil neighbor (i.e., heresy) butting up against it, eager to plant a crop of lies upon the sacred ground of God’s Holy Word and thus fool the saints. And the very reason that a spirit of error has encroached so far upon the truth in the last few years is because ministers have not walked the boundaries of the Gospel with their people and acquainted them with these primary truths.” —William Gurnall, The Christian In Complete Armor (emphasis added)