Summary: Any other Gospel doesn’t measure up to the "plumb line" of righteousness. Here are four reasons why.
Who can tell me what’s on the screen up there, Or what I’m holding in my hand? It’s a plumb line like the one mentioned in the Isaiah text we just read:
So this is what the Sovereign LORD says:
"See, I lay a stone in Zion,
a tested stone,
a precious cornerstone for a sure foundation;
the one who trusts will never be dismayed.
I will make justice the measuring line
The plumb line helps a builder to establish a true line square to the earth’s surface or straight up and down.
It’s a very simple tool and it hasn’t changed much since Isaiah’s time--sure we moderns have lasers to do the same thing over great distances and they’re not affected by the wind. But the simple device works great and you’ll find one at virtually any site where they’re laying brick. When I helped my dad lay a block foundation we didn’t have one so we made one with a string and a heavy nut--it works just as well. The point is the plumb line hasn’t changed much because the fact of gravity hasn’t changed much
The same is true of the Gospel message. It doesn’t change much--in fact it doesn’t change at all. There is one standard for all time, and that standard is the main thing that this letter to the Galatians is about. Here right after the Greeting the Apostle Paul makes his bottom line clear. The military writing coaches would be so proud, Bottom Line Up Front:
Proposition: Any other Gospel doesn’t measure up to the plumb line of righteousness.
Interrogative: In what ways are other messages lacking
Transition: Paul names four explicitly right up front the first is that they are...
v. 6 I am astonished that you are so quickly deserting the one who called you by the grace of Christ and are turning to a different gospel—
The confusion I’m thinking of is not that the things people exchange for the gospel are hard to understand-- although sometimes they are, but rather the confusion that Paul displays in verse 6 of why anyone would want to believe a message other than the true Gospel? It really is good news: Jesus died to pay the price for your sins, the debt has been cleared, simply put your trust in what he has done and eternal life is yours. What else could you want?
In the case of the Galatian churches, why would they exchange this good news for the bad news that there are other hurdles you have to clear to meet God’s expectations?
We can ask the same for virtually every form of false teaching and even false religions. Why would people trade the message of Salvation by God’s grace alone for a scheme that requires following a list of rules, or another which requires a new accounting for each misstep after the date of salvation?
On the other hand, why would you turn away from the glorious freedom from sin found in the law of the spirit to be bound again with the depressing chains of sin through the lie that says it doesn’t matter how you live once you believe in Jesus?
ILLUSTRATION: Raise your hand if you have kids who are at the "trading their stuff" stage? You people have an idea how Paul was feeling. "How could you trade your retainer for a garter snake?" "How could you trade your sneakers for a pudding snack pack?" "How could you trade your birthright for a bowl of soup?"