“Do all things without murmurings and disputings:” ( Philippians 2:14, KJV)
For Paul to say this means that the Christians at Phillipi were murmuring and complaining.
They were human. We tend to do that.
So, Paul tells us not to.
Just stop. No introspection required here. Just stop.
Complaining is unthankfulness. If you instead focus on thankfulness, you do a lot better.
“And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.” (Colossians 3:17, KJV)
“Giving thanks always for all things unto God and the Father in the name of our Lord Jesus Christ;” (Ephesians 5:20, KJV)
See? That was easy. Start small. Baby steps. Three weeks into trying to thank God for everything, it becomes a habit.