This passage in James is a warning about the danger of our words and their destructive impact due to the fact that we are broken and sinful beings. The writer James uses three common word pictures to drive home the point that, even though the tongue is a small part of the body, its negative impact can be quite large.
The first he mentions is a bit in a horse’s mouth. This is essentially the metal device that is connected to the leather straps that go around a horse’s head where the reins are attached. This device uses pressure or leverage when the reins are pulled to steer or control the horse. In this case a 4–6" wide device can steer a 5–6 foot tall, 2,200-pound animal. I will never forget being ten years old and nervously climbing up on the saddle of a big horse. They told me that, whatever I do, don’t let it go on the pavement because it would be bad for the horse’s feet. Next thing I knew, it bolted down the street with me barely hanging on, and I scream-cried until the horse finally decided to come to a stop. Probably user error on the whole bit and steering thing!
The second thing James mentions is a large ship which is steered by a very small rudder. The rudder is a flat piece which is hinged vertically to the stern (back) of the ship. When I was younger I spent a lot of my time on sailboats. My parents had a 26' O’day for years and then eventually upgraded to a 30' Hunter. I sailed in the Long Island Sound, San Diego Bay, as well as Lake Keowee in SC. The largest boat I ever sailed was on our family friend’s 40' Baba. Forty feet doesn’t sounds that big, but in boat world, especially sailboats, that’s a really big boat. As big as that boat was, I was even able to steer it as a 12-year-old boy by turning the steering wheel which moved a relatively small rudder and guided the massive sailboat through the wind and waves.
The third analogy is of a whole forest set on fire by a small spark. Like many boys, I was and still am intrigued by fire and burning stuff. One time in Miami, I was trying to melt some candlewax onto a curb for skateboarding tricks and accidentally caught some nearby leaves on fire. Good thing a neighbor lady came out running with buckets of water and a hose because what started out as a very small fire grew very quickly. Scarily, there was a gas station on the other side of the fence. We scrambled as fast as we could and eventually got the fire out as we doused the flames with water. It’s in situations like this where you realize just how quickly a fire can spread from the smallest little flame given the right (or wrong) conditions.
After those three vivid examples, the passage concludes with James plainly stating that no one can fully tame the tongue and that it is a restless evil full of deadly poison. He says that with it we praise God and curse men and how that shouldn’t be the case.