Bible Verses about “unthankfulness”

“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.”

“In every thing give thanks: for this is the will of God in Christ Jesus concerning you.”

“Because that, when they knew God, they glorified [him] not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.”