Isn’t legalism any time you teach change through external obedience? Not exactly. Legalism is either when you (a) feel closer to God when you do them, or (b) you put so much emphasis on developing the outward behavior that you neglect the inward change that comes only through faith in the gospel.
– Greear, J.D.; Gospel: Recovering the Power that Made Christianity Revolutionary; B&H Publishing Group; Nashville, TN; Copyright 2011; Kindle Edition; page 198