Legalism is but the human cry for personal autonomy. Doing things our way as distinct from trusting God’s power is illustrated just as clearly in modern evangelicalism as it is in the narrative of the wilderness wanderings. The inclination toward self-righteousness is thus not a unique Jewish problem: it is endemic to the human condition, and even the most deeply sanctified believer is vulnerable to its power.

Moises Silva, as cited in (Online source)