You shall know them, Jesus said, by their fruit.
The principle holds true for anything in life. It is especially helpful in diagnosing what the enemy might be up to. What is the fruit of what you’re experiencing? What is its effect? If it continues, what will the results of that be? What will be lost? Jesus said he came that we might have life and have it abundantly. He also warned that the thief comes to steal, kill, and destroy. Is something being stolen? That’s not from God. He called Satan the accuser of the brethren. Are you under accusation, that feeling of “I’m such an idiot”? (I’m using polite language here.) Look at the fruit—it will give you a good idea of the tree it came from.
Paul says that “the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control” (Galatians 5:22). I’m not feeling real joyful at the moment. In fact, the longer whatever this oppression is hangs around, the more discouraged I get. There’s not a lot of peace here either. Not like a river. Not even a rivulet. Whatever this cloud is I’m under, it isn’t bringing with it the fruit of the Spirit. I can’t get back to the clear air I normally have when I’m writing. Something is in the way. It’s vague, I can’t quite name it yet, but I sure can see the fruit of it. I can't write.