Too many people have assumed that believers may freely rebuke in their own authority, but there exists no scriptural basis for this. The LORD gave us an excellent example when He said, “The LORD rebuke thee, O Satan.” When rebuking the Devil, the LORD emphasized the importance of authority. No believer should ever rebuke except according to the God-given authority of scripture. In Zechariah 3:2, the LORD was His own authority, but believers do not have any such authority in themselves apart from the Lord and His word. Paul spoke expressly about this when he charged Titus to “speak, exhort, and rebuke with all authority” (Titus 2:15). It is not sufficient to flippantly invoke the Lord’s name; one must base any rebuke upon the scripture. Henceforth, it is the Lord that rebukes, never the believer.
The Bible says that “out of the abundance of the heart the mouth speaketh” (Matthew 12:34). This means that the words proceeding out of our mouths originate in our hearts. When we speak bitter words, it is because there is bitterness within our hearts. David likened bitter words to arrows that pierce the flesh (Psalm 64:3). Our words ought to be “seasoned with salt” (Colossians 4:6); instead, we often allow our words to pierce through others. We tear people down rather than building them up. Why is this? Because we have a root of bitterness growing inside that finds its way from our hearts into and out of our mouths. Those who demean others generally do so because they are bitter. Attempts to justify this behaviour are fruitless because the Lord knows the root of the problem stems from our heart.
