God hates it when we complain. There are several incidents in Numbers where the Israelites griped and the outcomes were disastrous (Numbers 16:41; 21:5-6). When we complain we are really saying, God is not looking after me the way he should, that he is keeping good things from me or he doesn't know what is best for me. When we complain we are saying that God isn't good enough.
The truth is that God is good regardless of our personal circumstances and he has already given us so much. He has given us love, peace, joy, eternal life, hope, grace, mercy, even his own Son. But when we complain we are saying this is not enough, we want more. We are like impertinent children the day after Christmas demanding more presents.
Yet complaining comes so naturally. It is not related to how much money we have or how much power we have or how intelligent we are. It is related to the attitude we have towards our circumstances. As Christians our attitude should be one of trust. Trust says whatever our circumstances God is in control and we accept whatever happens as coming from his hand. Complaining reveals our lack of trust. We don't trust God enough to believe he is working in everything for our good (Romans 8:28).
"Do everything without complaining or arguing … in a crooked and depraved generation, in which you shine like stars in the universe" (Philippians 2:14-15). This verse also gives us another very compelling reason not to complain. It tells us if we do not complain or argue it will be obvious to those around us that we are Christians. We will stand out like stars against a black world of sin and darkness.
Isn't it remarkable to think that we can have such a big impact by simply not complaining?