The term “legalism” is defined as striving to gain the approbation (attention or approval) of God, for salvation, by human good works. Legalism promotes self-righteousness — the deception of pride and ego-arrogance — hypocrisy.
Legalism is perhaps Satan’s most successful strategy to keep man from seeing God’s Grace. Legalism is pseudo-spirituality. It is Satan’s counterfeit of “the filling of the Spirit.” Legalism is motivated by arrogance. Legalism confuses morality with spirituality which results in the production of sin, human good, and evil. Legalism is human viewpoint which is contrary to Divine Viewpoint.
Think about this: If we could be good enough to go to heaven, then Christ did not need to go to the Cross. Salvation is provided by God! (John 3:15-18 & 36; Romans 5:8; Ephesians 2:8,9).