Complaining often falls into that category of sins that are excused because “that’s just so-and so.” However, God does not provide for such exceptions. Apparently, many people do not understand the extent of damage caused by the wagging tongues of negative naysayers. The apostle Paul told the Philippians, “Do all things without murmurings and disputings; That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world” (Phil. 2:14-15). According to Paul, if a person was a complainer, he was not blameless, harmless, or without rebuke, nor could he shine as a light to the world.
Complaining is very different from offering a scriptural objection. Complaining means that people have an objection to something—sometimes anything—but that they object for personal reasons rather than biblical reasons. If they had biblical reasons, they would cite scripture and explain their reasons for interpreting scripture differently. Instead, they want to get their way, and they will talk, gossip, nag, argue, and politic until they get their way.
While people, including those in the church, often give in to complainers just to “keep the peace,” God never does. Sometimes the squeaky wheel does not need grease at all. Sometimes there is a bunch of gunk getting in the way and keeping the wheel from operating properly. When this is the case, you do not add grease, you get rid of the gunk. Complaining is sinful and will cost you your soul. Therefore, “Neither murmur ye, as some of them also murmured, and were destroyed of the destroyer” (1 Cor. 10:10).
From Midtown church of Christ website