James 3:2–6 (NASB)
 For we all stumble in many ways. If anyone does not stumble in what° he says, he is a perfect man, able to bridle the whole body as well.  Now if we put the bits into the horses’ mouths so that they will obey us, we direct their entire body as well.  Look at the ships also, though they are so great and are driven by strong winds, are still directed by a very small rudder wherever the inclination of the pilot desires.  So also the tongue is a small part of the body, and yet it boasts of great things. See how great a forest is set aflame by such a small fire!  And the tongue is a fire, the very world of iniquity; the tongue is set among our members as that which defiles the entire body, and sets on fire the course of our life°, and is set on fire by hell°.
James 3:2 Lit word
James 3:6a Or existence, origin
James 3:6b Gr Gehenna
We all say things we shouldn’t, so much so that James says here that if you don’t ever fall short in your talking, that you’ve attained perfection. Now, this isn’t to say that, “not saying bad things is all that’s required,” but rather that, what comes out of your mouth is indicative of what’s in your heart, which controls all of your actions. Since the tongue is essentially directly connected to your heart, it is either a very powerful tool or weapon. Your life and even others’ lives can be dragged around by it, like in the horse example, or regardless of the storms you face, you can traverse the waters of life.
More often than not, however, our tongue starts forest fires of destruction. Some people live their whole lives carrying the burden of “one small thing” said to them as a child (that the other person may not even remember saying). The things we say can open up spiritual doors on someone, often leading to a lifetime of demonic oppression. We can speak shame on someone, tell them to shut up, tell them that they’re stupid, worthless, and worse.
In verse six, James says that the tongue is “the very world of iniquity.” The word translated here as “world” (kosmos G2889, kaw’-smaws) is the word we get “cosmos” directly from, and basically means “all of creation.” So, the idea here is that the things we say are the very universe in which sin resides. He goes on to say in the same verse that the tongue “defiles the entire body.” The word translated here as “defile” (spiloo G4695, spee-law’-oh) means “to stain, soil, or blemish.” Few things can stain your ministry quicker than the words from your mouth.
By our own power, we may be able to resist saying these things and we may be able to cope despite the burdens and oppression from hearing these things. However, it is only through the power of Christ and the Holy Spirit working within us that we can truly overcome these things.
Titus 3:3–7; Ephesians 5:25–27; Romans 8:26–27; Romans 8:35–39