Complaining is a sin! It is a corrupt form of conversation that causes many people a great deal of problems in their lives. It also opens many doors for the enemy. Words are containers of power. Complaining, grumbling words carry destructive power. They destroy the joy of the one doing the complaining and can also affect other people who have to listen to them.
In Ephesians 4:29, the apostle Paul instructs us not to use any foul or polluting language. At one time I would not have known that included complaining, but now I have learned that it does. Murmuring and complaining pollute our lives and probably sound like cursing to the Lord. To Him it is verbal pollution. To pollute is to poison. Did you ever stop to think that you and I can poison our future by complaining about what is going on right now?
When we complain about our current situation, we remain in it; when we praise God in the midst of difficulty, He raises us out of it. The best way to start every day is with gratitude and thanksgiving. Get a jump on the devil. If you don't fill your thoughts and conversation with good things, he will definitely fill them with evil things. Truly thankful people do not complain. They are so busy being grateful for the good things they do have that they have no time to notice the things they could complain about. Praise and thanksgiving are good; complaining and grumbling are evil.