I think it's important for all of us to understand what our Achilles' heel is, spiritually speaking.
According to Wikipedia, an Achilles’ heel is a fatal weakness in spite of overall strength, actually or potentially leading to downfall. While the mythological origin refers to a physical vulnerability, metaphorical references to other attributes or qualities that can lead to their downfall are common.
You can recognize when your spiritual Achilles' heel has been hit. It usually causes you to question your faith, doubt your motives, or even judge yourself unfairly. Do I believe that there are those running around taking aim at our Achilles' heel, trying to undo us? No. I believe must people hit it in total ignorance, not realizing that "soft spot" that causes us to double over, spiritually speaking.
Where does a spiritual Achilles' heel come from? I want to suggest several sources. Maybe you will be able to expand on my line of thinking and discover more of your own.
1) Shame. We have all screwed up. Even if we have repented, received forgiveness and moved on, every so often, shame will rear its ugly head. For example, let's say you once were caught stealing on the job. Perhaps you make full retribution. Then let's say that years later, someone implies that you are being dishonest on the job, perhaps even innocently. It can spring the guilt and shame trap. It can set you back. It can cause the voices within to say, "Yeah, remember that other time, and we know what you're thinking all the time, how you'd like to get more of what you deserve around here, you know you're just as good as guilty, whether you did it or not!"
2) Righteous indignation or injustice. Perhaps you truly seek to do the right thing most of the time, yet you find yourself under scrutiny for something. You may even feel astonished, aghast, that anyone would think you could stoop so low. Or you feel stupid for not recognizing how someone might misunderstand a situation. Then you say ... Hey, are they seeing something I don't see? Am I fooling myself? Am I in denial? Do I think about stuff like that? Is that something I really might be seriously tempted to do? The experience is even more piercing the more reputable the person who calls you into question.
3) Unconfessed sin. This one is probably the most dangerous because it is the most legitimate. Any unconfessed sin in our lives is going to feel like a poke in the eye with a sharp stick if we come under fire for it or something similar. You might say, What would I do if someone found out about THAT? Maybe everyone is on to me. Maybe everyone knows that I am really a fake. Maybe everyone will think I am a hypocrite. The effect of this Achilles' heel is multiplied significantly if we feel that we have let others down or caused a bad light to shone on another person or entity.
So why do we need to dwell on this spiritual Achilles' heel? Well, according to the original Greek myth, Achilles was caught off guard; that was his true downfall. At the risk of sounding fanatical, I will say that from time to time, we are all victims of the enemy's potshots at our Achilles' heel. Realize that he doesn't always come after us in a clearly recognizable way. No one with horns, a beard, long tail and pitch fork is suddenly going to walk up to you and say, "Do you really think someone with your history should take on that responsibility?" No, many of us are unwittingly used to strike the Achilles' heel of another. I have to stop now and ask myself, are there times when I have lost my temper, said something I should not have, judged someone unfairly, been careless in word and action, and hit the Achilles' heel of another? Here I was, just going off, not realizing the ramifications. Wouldn't we all be aghast if the enemy emailed us a list of the times he used us for this very purpose?
So by being aware of the areas in our own lives that represent the potential for a spiritual Achilles' heel, we can get free and beat the enemy to the punch. By understanding that we are often used against our own wills or awareness to bring down another, we hopefully can stop to reflect the real damage that might be inflicted by none other than ourselves.
As we learn to recognize the potshots, we learn to deflect them. We learn to say, "You have no power over me. Get behind me." We understand that others aren't always out to hurt us. Sometimes they are being used.
Is the invisible spiritual world really this involved in your life? Could evil really be all that concerned with little old you? Take enough hits to the Achilles' heel and you'll have your answer.