Bible Verses about “unthankfulness”

“Whatever you do, in word or in deed, do all in the name of the Lord Jesus, giving thanks to God the Father, through him.”

“In everything give thanks, for this is the will of God in Christ Jesus toward you.”

“Because, knowing God, they didn't glorify him as God, neither gave thanks, but became vain in their reasoning, and their senseless heart was darkened.”