However applicable this profound verse might be to construction projects and sentry duty, the deeper truth refers to the spiritual work done through us. Both clauses in this verse are making the same point: attempting to do anything in God’s kingdom in the flesh is an utter waste of time.
It also implies another truth: there must be a proper balance in human effort and faith-filled trust in the Lord. Many times I have witnessed ministers (including myself) err in one direction or the other.
Some imagine that they are going to “trust God” to accomplish important kingdom work when the reality is that they simply don’t want to pay the required price involved in true gospel work. They piously say they are waiting on the Lord, but in truth, they simply want everything handed to them. Such was the servant who “hid his talent in the ground” and has had the epitaph written on his life that he was a “wicked, lazy slave.” To live out the love of God to needy people is no easy task. It means bearing them to God in prayer, sharing in their sufferings, sometimes even being the object of their hostility. The apostle Paul was a shining example of someone who bore the marks on his body of someone willing to pay a dear price to bring the gospel to the lost.
On the other extreme are those who attempt to do God’s work in their own strength. I would break this group into two categories. First, there are hirelings who are in it for their own purposes. If they have a prayer life at all it is very minimal and self-focused. They are driven by ambition and measure results in terms of outward signs of success. They are building a house, but it is like the monument Saul built for himself. When they stand before God one day—and stand they will—they will be confronted with the reality that all of their efforts in God’s name have really been for themselves.
The second group of people who fall into the category of depending upon their own efforts are those who have sincerely attempted to serve God but for one reason or another, have gradually and unknowingly slid into self-trust. In our hectic day and age, it is very easy for ministers to become so busy that a subtle change begins to take hold of their efforts. When overwork begins to drain them spiritually, they can get out of the flow of God’s grace. Before they realize what has happened, they are operating in the flesh, worrying about the lack of results, doubling their efforts, becoming even more taxed… well, I think you can see how a person can slide into self-efforts without realizing it. This is a struggle I understand all too well.