Who Taught Christians That Discipline Was Legalism?

And when you⁺ may fast, do not be as the hypocrites, gloomy-faced; for they disfigure their faces so that they might appear to men [as] fasting. Truly I say to you⁺, they have their reward in full.

Matthew 6:16, Berean Literal Bible

But you, fasting, anoint your head and wash your face,

Matthew 6:17, Berean Literal Bible

so that you might not appear to men [as] fasting, but to your Father, the One in secret. And your Father, the One seeing in secret, will reward you.

Matthew 6:18, Berean Literal Bible

Therefore do not let sin reign in your⁺ mortal body, in order to obey its desires.

Romans 6:12, Berean Literal Bible

Neither present your⁺ members to sin [as] instruments of unrighteousness, but present yourselves to God as living out from the dead, and your⁺ members to God [as] instruments of righteousness.

Romans 6:13, Berean Literal Bible

Therefore I exhort you⁺, brothers, through the compassions of God, to present your⁺ bodies [as] a living sacrifice, holy to God, well-pleasing, which is your⁺ reasonable service.

Romans 12:1, Berean Literal Bible