James 3:12

Can? The Greek implies that a negative answer is expected.

Fig tree. Fruit trees and springs of water produce according to their respective natures. No other result is expected. James here suggests that cursing and other abuses of the tongue obviously mark a person as not a genuine Christian. He does not imply that a converted person never lapses into sin (cf. v. 2), but he does show that a truly converted person will not make a practice of engaging in un-Christlike speech (see on v. 10).

Vine. The illustrations here used resemble those employed by Christ (see Matt. 7:16). James is not primarily contrasting good with bad, but insists that a tree must produce “after his kind” (Gen. 1:11, 12) and that, conversely, the nature of the fruit inevitably testifies the kind of tree that produced it (see Matt. 7:20).

So. Textual evidence favors (cf. p. 10) the reading of the last clause of v. 12 as follows: “Neither can salt water produce fresh water.” James here shows that it is impossible for true worship to come from a heart of evil. His conclusions are especially applicable to teachers.