One of the things I believe grieves the heart of God is when His children grumble and complain. In Jude 6 we find some interesting insight into this destructive behavior,
These are grumblers, complainers, walking according to their own lusts; and they mouth great swelling words, flattering people to gain advantage.
The word complainer is really two Greek words stuck together. The first word means to blame, and the second word means your fate or lot in life. The point is that complainers blame someone else for their lot in life.
Isn't it always amazing how someone can make wrong choices, and when they have to face the consequences of those choices, it is always somebody else's fault?
I have two pieces of advice for you on this. First, if you are a complainer and grumbler, stop. God is not honored, and you are only showing that you are "walking according to your own lust," not according to God's Spirit.
Second, stay away from people like that or you will end up being like them. Proverbs -25 says,
Make no friendship with an angry man, and with a furious man do not go, lest you learn his ways and set a snare for your soul.
Their attitudes and mindsets will bleed off on you.
Did you ever throw a pair of jeans in the washing machine with a red shirt? What happened to your blue jeans? They turned pink, didn't they? The red dye bled over into the blue jeans, and the blue jeans were no longer blue. They were pink.
If you hang around with people who grumble and complain, their attitudes will bleed over into your way of thinking. And the last thing you want to be is a grumbler and complainer.