When our Lord and Master Jesus Christ said, 「Repent」 [Matt. 4:17], he willed the entire life of believers to be one of repentance.
This I assert and in no way doubt.
1. Nevertheless, I shall prove the thesis for the sake of those who are uninformed, first from the Greek word Μετανοεῖτε itself, which means 「repent」 and could be translated more exactly by the Latin transmentamini, which means 「assume another mind and feeling, recover one’s senses, make a transition from one state of mind to another, have a change of spirit」; so that those who hitherto have been aware of earthly matters may now know the spiritual, as the Apostle says in Rom. 12[:2], 「Be transformed by the renewal of your mind.」
By this recovery of one’s senses it happens that the sinner has a change of heart and hates his sin.
It is evident, however, that this recovery or hatred of oneself should involve one’s whole life, according to the passage, 「He who hates his soul in this life, preserves it for eternal life」
[Matt. 10:39]. And again, 「He who does not take his cross and follow me, is not worthy of me」
[Matt. 10:38]. And in the same chapter, 「I have not come to bring peace, but a sword」
[Matt. 10:34]. In Matt. 5[:4], 「Blessed are those who mourn, for they shall be comforted.」
And Paul in Romans 6 and 8 and in many other places orders us to mortify the flesh and members of the body which are upon earth. In Gal. 5[:24] he teaches us to crucify the flesh with its lustful desires. In II Corinthians 6 he says, 「Let us show ourselves in much patience, in many fastings, etc.」
[Cf. II Cor. 6:4–5]. I produce these citations so extensively because I am dealing with those who are unacquainted with our teachings.
2. I shall prove this thesis also according to reason. Since Christ is the master of the spirit, not of the letter, and since his words are life and spirit [John 6:63], he must teach the kind of repentance which is done in spirit and in truth, but not that which the most arrogant hypocrites could do openly by distorting their faces in fasts and by praying in streets and heralding their giving of alms [Matt. 6:16]. Christ must teach a repentance, I say, which can be done in every, walk of life, a repentance which the king in purple robes, the priest in his purity, and the princes in their dignity can do just as well as the monk in his rituals and the mendicant in his poverty, just as Daniel and his companions did in Babylon [Dan. 1 and 3]. For the teaching of Christ must apply to all men, that is, to men in every walk of life.
3. We pray throughout our whole life and we must pray 「forgive us our debts」
[Matt. 6:12]; therefore, we repent throughout our whole life and are displeased with ourselves, unless anyone may be so foolish as to think he must only pretend to pray for the forgiveness of debts. For the debts for which we are commanded to pray are real and not to be treated lightly; and even if they were venial, we could not be saved unless they were remitted. (AE 31:83–85)