Note 23 at Eph. 4:29: The Amplified Bible translates this verse as, "Let no foul or polluting language, nor evil word, nor unwholesome or worthless talk ever come out of you mouth; but only such speech as is good and beneficial to the spiritual progress of others." There is no doubt that this is speaking of more than just cursing or profanity. Gossip, slander, and jesting which is not appropriate (Eph. 5:4) would be included also. Certainly griping and complaining would not be considered speech that would encourage others either.

Note 24 at Eph. 4:29: All of our speech is supposed to edify (see ref. c at this verse) and encourage others in the goodness of God. If some Christians took this verse to heart, they would have to develop a whole new vocabulary. Profanity is obviously wrong, but many Christians think gossip, criticism, and complaining are God-given rights. That's not what Paul is promoting here.