"Beloved, when I gave all diligence to write unto you of the common salvation, it was needful for me to write unto you, and exhort [you] that ye should earnestly contend for the faith which was once delivered unto the saints" (Jude 3). "Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine" (2 Timothy 4:2). "This witness is true. Wherefore rebuke them sharply, that they may be sound in the faith" (Titus 1:13). "But speak thou the things which become sound doctrine" (Titus 2:1). "Wherefore I will not be negligent to put you always in remembrance of these things, though ye know [them], and be established in the present truth" (2 Peter 1:12).