Neither filthiness, nor foolish talking, nor jesting, which are not convenient: but rather giving of thanks. Ephesians 5:4. OHC 292.1
A man's character may be quite accurately estimated by the nature of his conversation.... Those who jest and joke and indulge in cheap conversation place themselves upon a level where Satan can gain access to them.... When you associate together, you may be a help and a blessing one to another if you surround yourselves with an influence that is divine. But there are those who have grave defects, which are gaining a deeper hold upon them and which if not overcome will drive the Spirit of God out of the heart.... Jesting and joking may please a class of cheap minds, and yet the influence of this kind of conduct is destructive to spirituality. I speak to you as a class and also as individuals: Guard your words. Let sobriety and sound common sense characterize your conversation. Do not trifle with the purity and nobility of your souls by condescending to indulgence in stale jokes, and in cultivating habits of trifling conversation. OHC 292.2
The requirement of God is explicit on these points, and presents before you the obligations that rest upon you as children of God. The Word of God says, “Whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.” Colossians 3:17.22Letter 2, 1895. OHC 292.3
O that every one of our youth would realize the evil of foolish conversation, and correct the habit of speaking idle words! Let every one who has indulged in this sin repent of it, confess it before God, and put it far from him. In speaking foolish words, you have dishonored the name of Christ; for you have misrepresented Him in character. No word of guile was found in His lips, no word of prevarication or falsehood. The people that are described as making up the one hundred and forty-four thousand, have the Father's name written in their foreheads, and of them it is said: “In their mouth was found no guile: for they are without fault before the throne of God.” Revelation 14:5.23The Youth's Instructor, June 27, 1895. OHC 292.4