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.
The foregoing chapter shows how unprofitable and dead faith is without works. It is plainly intimated by what this chapter first goes upon that such a faith is, however, apt to make men conceited and magisterial in their tempers and their talk. Those who set up faith in the manner the former chapter condemns are most apt to run into those sins of the tongue which this chapter condemns.
Commenting on James 3:1-12
Behold also the ships, which though they be so great,.... Of so large a bulk, of such a prodigious size, and are such unwieldy vessels: and are driven of fierce winds; with great vehemence, rapidity, and swiftness: yet are they turned about with a very small helm, whithersoever the governor listeth; the helm, or tiller of a ship, is a beam or piece of timber...
Verse 4. Behold also the ships. This illustration is equally striking and obvious. A ship is a large object. It seems to be unmanageable by its vastness, and it is also impelled by driving storms. Yet it is easily managed by a small rudder; and he that has control of that, has control of the ship itself. So with the tongue.