Philippians 2v14
Do all things without grumbling or questioning, 15 that you may be blameless and innocent, children of God without blemish in the midst of a crooked and twisted generation, among whom you shine as lights in the world, 16 holding fast to the word of life

Criticism and complaint can be a dangerous disease that robs us of the incredible blessings and lessons God wants to teach us in those moments. We dim the light of God when we fall to complaint and criticism and this is where we deny ourselves, take up our cross, and do our duty as followers.