Tullian Tchividjian said this quote
“ one primary enemy of the Gospel—legalism—comes in two forms. Some people avoid the gospel and try to save themselves by keeping the rules, doing what they’re told, maintaining the standards, and so on (you could call this “front-door legalism”). Other people avoid the gospel and try to save themselves by breaking the rules, doing whatever they want, developing their own autonomous standards, and so on (you could call this “back-door legalism”). ”