Did you ever wonder why nominal Christians give you grief when you insist that salvation is by grace through faith alone apart from any good works (Eph. 2:8,9)? The Apostle Paul understood the reason that men troubled him for proclaiming this message, and he came up with the perfect illustration to help the Galatians understand it. Speaking of the two sons of Abraham, he observed:
“But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now” (Gal. 4:29).
When we look up the passage that Paul is quoting here, we learn that Ishmael “persecuted” Isaac by “mocking” him (Gen. 21:9). And, if you know the story, you know why Ishmael was giving his younger brother grief. When Abraham got tired of waiting for God to give him the son He had promised, he took matters into his own hands and fathered a child by his wife’s servant, intending to make Ishmael the heir that God had promised (Gen. 17:18). God rejected this notion (Gen. 17:20,21) and eventually gave Abraham the son that He promised through the miraculous birth that Abraham’s wife Sarah gave to Isaac.
Ishmael was thirteen years old (Gen. 17:25) when Isaac was weaned (Gen. 21:8), and based on his father’s assurance that he would be his heir, he had doubtless worked very hard to be worthy of his inheritance. Then suddenly there appeared this interloper, this young child Isaac, whom Sarah rightly declared would be her husband’s heir (Gen. 21:10), and God agreed (Gen. 21:12). That meant that after all Ishmael’s hard work his inheritance was now going to be just handed to this infant who hadn’t done a thing to earn it other than to be born the child of promise.
Now, if you can’t relate to the anger that Ishmael felt toward the newly-declared heir, I certainly can! When I was twelve, I asked my father to buy me a Schwinn Fastback Stingray bicycle. He informed me that I was old enough to work for the money that would be needed to make such an expensive purchase. He then reminded me that I could work as many hours as I wanted at his tool and die shop. To help me out, he graciously bumped my salary up to 50 cents an hour (he had started me out at 15 cents an hour!). But while I was working and saving for my $75 bike, my younger brother learned to ride a bike, and was given—a Stingray bicycle! I remember feeling angered that he had just been handed something for which I was having to work so long and hard!
That explains how Ishmael felt about Isaac, which in turn explains how professing Christians feel about those of us that champion the cause of salvation by grace through faith apart from works. Such “Christians” are angered at the notion that the salvation for which they themselves are working so long and so hard is being offered so freely to men and women who haven’t done a thing to earn it other than to be born again a child of God’s promise (Gal. 4:28).
How should we respond to such religious animosity? Paul answers in the opening words of the very next chapter in Galatians: “Stand fast therefore in the liberty wherewith Christ hath made us free” (Gal. 5:1)! It has never been easy to stand for the pure, unadulterated gospel of the grace of God, but as the old hymn of the faith expresses so very well, “it will be worth it all when we see Jesus”! source