[1] Not many of you should become teachers, my brothers, for you know that we who teach will be judged with greater strictness. [2] For we all stumble in many ways. And if anyone does not stumble in what he says, he is a perfect man, able also to bridle his whole body. [3] If we put bits into the mouths of horses so that they obey us, we guide their whole bodies as well. [4] Look at the ships also: though they are so large and are driven by strong winds, they are guided by a very small rudder wherever the will of the pilot directs. [5] So also the tongue is a small member, yet it boasts of great things.
How great a forest is set ablaze by such a small fire! [6] And the tongue is a fire, a world of unrighteousness. The tongue is set among our members, staining the whole body, setting on fire the entire course of life, and set on fire by hell. [7] For every kind of beast and bird, of reptile and sea creature, can be tamed and has been tamed by mankind, [8] but no human being can tame the tongue. It is a restless evil, full of deadly poison. [9] With it we bless our Lord and Father, and with it we curse people who are made in the likeness of God. [10] From the same mouth come blessing and cursing. My brothers, these things ought not to be so. [11] Does a spring pour forth from the same opening both fresh and salt water? [12] Can a fig tree, my brothers, bear olives, or a grapevine produce figs? Neither can a salt pond yield fresh water.
(James 3:1-12 ESV)