Diligence is the second “let us” resolution that occurs in the fourth chapter of Hebrews: “Let us therefore be diligent to enter that rest, lest anyone fall through following the same example of disobedience” (Hebrews 4:11 nasb).
I pointed out previously that this warning is based on the experience of the Israelites on their journey from Egypt through the wilderness. Most of them did not make it through to the Promised Land—the destination and rest that God had promised them—because of their misconduct and wrong attitudes. And they fell in the wilderness. Scripture says that their carcasses fell in the wilderness because of unbelief and disobedience. (See Numbers 14:29, 32.) And through unbelief and disobedience, they failed to hear the voice of the Lord. They had the externals, but they did not have the great essential, inner reality of all true religion—hearing the voice of the Lord.
So, that was the mistake of Israel—a tragic mistake. After saying, “Let us fear” (Hebrews 4:1), the writer of Hebrews went on—still on the basis of the example of Israel—to say, “Let us be diligent.” I believe that is very natural. If we really take to heart the dangers of that spiritual condition and do fear, in that sense, the next thing we will naturally do is become diligent.
Let’s consider for a moment what diligence is. One way to find out the meaning of a word is to consider what its opposite is. An obvious opposite of diligence is laziness. The Bible does not have one good word to say about laziness. It is a theme that does not receive enough attention in contemporary Christendom.