Grumbling! Who doesn't like a good grumble or an opportunity to complain about something or anything? We must recognize these responses as red-flags to underlying anger in our heart. Unfortunately, we tend to allow these subtle versions of anger to remain and we can even justify these responses. When we willingly refuse to address these "quieter" sins, we will soon be dealing with entrenched forms of anger. Grumbling and complaining affect our relationships with others (who wants to be around a complainer?), and more importantly they reveal what is going on in our relationship with God: we are refusing to submit to His ways, see His goodness, trust His sovereignty, and we are expecting that He meet our demands.
We must realize that God takes our grumbling seriously. He does not just give it a wink and look for more serious matters. Grumbling and complaining are serious sins against God. Exodus 16:8 states that grumbling is always against God. It reveals our heart and the conclusion is that God is not good or trustworthy. In Numbers 11, the people of Israel complained against God. These people had withdrawn to the outer parts of the camp (away from God's dwelling in the tabernacle) and God sent down fire to consume them. Does God view complaining as a minor sin? There are few sins that He addressed with a consuming fire, but grumbling and complaining make the list!
In Numbers 14 the people complain once again. They direct it at Moses, but he reminds them that their complaint is actually against the sovereign God. It is an act of contempt against God and it says that we despise Him. Ed Welch states "Grumbling is spiritual adultery." Interestingly enough, it is also in this passage where some of the most powerful statements of God's attributes regarding grace, mercy, and love are made in response to sin.
Paul addresses this issue in Philippians 2:14-15. In his words, there is no room, no place, no time, and no excuse for grumbling or complaining. We are not to do it! He takes the negative implications even further by stating that not only is our perspective of God skewed when we complain, but that the world around us will have a wrong view of God. Complaining and grumbling, even if it seems to be deserved because of bad service, bad drivers, bad politicians, bad bosses, etc. or even if we are old and grumpy, distorts the light of truth about God and the good news of Jesus Christ. The impact of grumbling and complaining has the potential to be eternal because we turn people away from God. Grumbling and complaining are serious sins.
Do not allow the sin of anger in the form of grumbling and complaining to remain or take root in our heart.