James 1:22-25, ESV
"But be doers of the word, and not hearers only, deceiving yourselves. For if anyone is a hearer of the word and not a doer, he is like a man who looks intently at his natural face in a mirror. For he looks at himself and goes away and at once forgets what he was like. But the one who looks into the perfect law, the law of liberty, and perserveres, being no hearer who forgets but a doer who acts, he will be blessed in his doing."
Now I'm no theology student, but I will take a stab at putting this in very plain English. The ESV (English Standard Version) is supposed to be a very, very-close-to-literal translation from Greek to English, but that doesn't mean it translates into typical modern American speaking terms and phrases seamlessly.
Basically, what James is writing in this verse is: Read the Bible (God's Word), keep what God says through his Word close to your heart and in your mind, and then live it out. Every day. To every one.
He's also saying, very loosely paraphrased, that if you read the Bible and then go about the rest of your day acting like you didn't just read the passages that say "don't gossip, respect your master, love your brothers in Christ, care for the orphans and widows" (just a sampling), you are being rather obtuse. Because you're like a person who looks at himself in a mirror, walks away, and can't remember what you look like.
And sure, it's easy to laugh and assume you'd never do that. But then the day starts and well, I won't go into details, but soon enough, I'm gossiping or whining about my work or feeling put-upon by a well-meaning acquaintance or getting really, blown-out-of-proportion irritated by the slow-moving vehicle in front of me.
So I turn to prayer. And just pray that God will work in me every day, in every way.