Achilles was a vicious warrior with a complicated history. In Homer's Iliad we see him rise to the top as the preeminent player at the end of the Trojan War. His full backstory is melodramatic enough to make Downton Abbey blush, but suffice it to say that no one was quite like him. Achilles was simultaneously drunk in rage and meticulous in skill as he led the Greeks in battle. But most of us probably only know him because of his heel.
Achilles doesn't die in Homer's story but Greek legend says that he later suffered a mortal wound to the back of his foot. The "Achilles' heel," as it's called today, has become one of the most popular idioms in Western culture. It refers to a person's point of weakness leading to their downfall.
But that idea comes from Greek mythology, not Christian reality.
God's wisdom gives us another picture. Believers in Jesus don't have an Achilles' heel -- we are an Achilles' heel.
Here's what I mean: Greek mythology shows us an invincible warrior with one weakness that when exploited leads to defeat; Christian reality shows us a dependent servant with thorough weakness that when exploited leads to triumph.
That's our story. That's the trail that Jesus blazes (1 Peter 2:21). A hero died for villains. Victory came through loss. Life was born out of death. Conquest was accomplished by suffering. The darkest night in history gave way to the brightest morning. In God's economy, our weakness is one of our greatest assets.
Now what do we mean by weakness? The word has such a general meaning that we must sketch some type of definition before we go any further. First, let's be clear about what weakness is not. The biblical concept of weakness does not mean the things we're not good at. We're tempted to think this way. It would be easier if weakness were contained to the things we stink at doing. But it's much more pervasive than that. We can't simply tip-toe around it.
Weakness is everywhere in the New Testament.
[Read the rest of the article at Desiring God.]