Though few tools are simpler than a plumb line, few are more effective at their task. A plumb line is simply a pointed weight—a plumb bob, or plummet, if you prefer—that has been suspended from a cord. The bob dangles from the cord and, through the consistent downward pull of gravity, establishes a vertical reference. Since time immemorial—ancient Egypt at least—a plumb line has been used to establish verticality for walls, towers, castles, and other structures. If you make a careful study of the floors of the great cathedrals of old, you may spot the marker that indicates where one used to hang, the reference point for the entire building.
The prophet Amos once saw a vision that involved a plumb line. He saw the Lord standing beside a wall with a plumb line in his hand. Amos looked and realized that the wall was not perfectly parallel to it. In fact, the line showed that the wall was leaning, that it was dangerously buckled. Amos might have been tempted to try some repair work, but the Lord warned that the wall was too far out of the vertical to be fixed. It was only a matter of time before it gave way and collapsed.
God has little interest in walls, but great interest in people, and this vision was meant to make the point that Israel had become dangerously out of alignment with the law of God. God had graciously called this nation to be his people, his own chosen possession. He had given them his law, he had revealed to them the blessings that would be theirs with obedience and the curses that would come upon them with disobedience. He had shown his favor by saving and redeeming them time and again. Yet still they had turned aside, still they had been a law to themselves. And now, God told them, they had gone so far that mercy would have to give way to wrath, life to death, blessings to judgment. The plumb line had revealed the extent of their leaning—the extent of their rebellion—and had sealed their fate.
Each person lives according to a law, according to a standard of morality. None of us lives without rules. Even the most committed subjectivist will balk when another man harms his body or steals his possessions. Though most people deny and suppress it, the law of God is written on our hearts with its cry for equity, for justice, for law. That being the case, what distinguishes the standards of Christians from those who hold to other rules, other laws? The plumb line holds the answer.
A plumb line hangs from a point that has been fixed above it. As long as the laws of gravity remain intact, that line will always hang perfectly straight so that whatever parallels it will be equally straight. A tower whose four walls parallel the plumb line hanging in its center is a tower that is perfectly formed. It will stand tall and strong through the ages.
But imagine if the builder of that tower had taken that same line and anchored it below instead of above. Imagine if he tied the end of the cord to the ground and then lifted the plumb bob to what he perceived to be a point directly above. Imagine if he had set his vertical alignment from the ground instead of to the ground. Even the most skillful builder with even the best eye would still get it wrong. He might be 4 degrees out of alignment and create another Tower of Pisa, or maybe he would be off by only 2 degrees, but he would certainly not be able to create a perfect vertical. It would take only the smallest error at the bottom to lead to gross misalignment at the top.
Every faith and every system of morality apart from Christianity begins at the bottom. It fabricates standards from the minds of men, then adheres to them in an attempt to reach upward and gain the favor of God. Since it begins at the bottom, it is never in perfect alignment; it is always and forever askew. “Fools!” exclaims old Talmage. “Why will you stand at the foot of the wall measuring up when you ought to stand at the top measuring down?” Only the Christian faith begins at the top. We are made right with God first, then obey his law as it is suspended from above, as it is revealed from the heavens. His plumb line is perfect and true, and we work out our salvation with fear and trembling by constantly comparing our lives to it. Just as a tower is straight only to the degree to which it matches the builder’s perfect line, our lives are right only to the degree to which they match God’s perfect law. It is our faith, and our faith alone, that ends at the right place, for it is our faith, and our faith alone, that begins at the right place. By God’s grace, we have been taught to measure down, not up.
(Inspired by Trumpet Peals by Thomas De Witt Talmage)