When we complain, it is frequently evil. But complaining is not necessarily evil. There's a faithful (believing) way to complain and a faithless (unbelieving) way to complain. The Bible often refers to faithless complaining as grumbling and warns us not to do that (Numbers 14:26–30; John 6:43; Philippians 2:14; James 5:9). Grumbling complaints directly or indirectly declare that God is not sufficiently good, faithful, loving, wise, powerful, or competent. Otherwise, he would treat us better or run the universe more effectively. Faithless complaining is sinful because it accuses God of doing wrong.
But faithful complaining does not impugn God with wrong. Rather, it is an honest, groaning expression of what it’s like to experience the trouble, anguish, and grief of living in this fallen, futile world (Romans 8:20–23). God does not mind this kind of complaining. In fact, he encourages it — and teaches us how to do it in the Bible.
With my voice I cry out to the Lord; with my voice I plead for mercy to the Lord. I pour out my complaint before him; I tell my trouble before him. (Psalm 142:1–2)
How God Wants Us to Complain
Most of these biblical and righteous complaints are contained in what we call the psalms of lament. The Book of Psalms contains the prayers and hymns that God chose to teach us how to express ourselves to him in worship. About one-third of these psalms are laments. And they are precious gifts from God.