Paul spoke to the Galatian churches in frustration because after receiving the Spirit of God freely by faith, they had been persuaded to begin trusting in the works of the old law in addition to faith in Christ. Paul called this a work of the flesh. Its roots go back to the same tree Adam ate from when everything collapsed. It was called The Tree of the Knowledge of Good and Evil. It was an unbelief problem as Adam decided to turn from trusting in the sufficiency of the life of God … and chose to begin trusting in the knowledge of both good and evil. He was told it would make him more like God, but it had the opposite result.
Many believers today are struggling with the same thing. They are working at trying to become more like God, and it becomes more about doing—or not doing—instead of being or resting in who God has already made them to be.