1Joh 2:1 must be a reference to sins of ignorance (sin not unto death) for if it was a reference to willful rebellion then John is making a case for easy forgiveness.
In Hebrews it speaks of no sacrifice remaining for willful sin after a true cleansing. The cleansing in Heb 10:22 is obviously the same cleansing alluded to by John in 1Joh 1:7 and 9.
We have an advocate for sins of ignorance (1Joh 2:1) but willful sin requires godly sorrow working a repentance unto salvation (unto a true once and for all cleansing).
To imply otherwise is to argue in favour of a sin/repent/sin/repent/sin/repent (dirty/wash/clean over and over) cycle which is obviously at odds with any notion of a pure heart without guile.
This is one error I think many of the "stop sinning" street preachers do not perceive.
To further clarify.
In Hebrews the cleansing is presented in the context of being a once and for all and that is why "if we willfully sin there remains no more sacrifice for sin."
This...
Heb 10:22 Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
and this...
1Jn 1:7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
and this...
1Jn 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
... is not intended to be a cleansing which occurs over and over again. We are cleansed in order to remain clean. Grace is mocked when the cleansing is viewed as some kind of lever to be used again and again...
Heb 10:26 For
if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
Heb 10:27 But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
Heb 10:28 He that despised Moses' law died without mercy under two or three witnesses:
Heb 10:29 Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?
If 1Joh 2:1 was a reference to willful sin then it would mean that a sacrifice for sin does remain and thus it would be a clear contradiction to Heb 10:26.
If we look at how Paul described "godly sorrow that works repentance"...
2Co 7:10 For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death.
2Co 7:11 For behold this selfsame thing, that ye sorrowed after a godly sort, what carefulness it wrought in you, yea, what clearing of yourselves, yea, what indignation, yea, what fear, yea, what vehement desire, yea, what zeal, yea, what revenge! In all things ye have approved yourselves to be clear in this matter.
... notice he referred to "approved yourselves to be clear in this matter."
The word clear in the Greek is...
hagnos
From the same as G40; properly clean, that is, (figuratively) innocent, modest, perfect: - chaste, clean, pure.
In other words, the matter in question has been dealt with at the HEART LEVEL in the repentant individual. There is no returning to this sin.
Godly sorrow works a repentance unto salvation. In other words godly sorrow effect a true change of the inward man whereby the outcome is wholehearted submission to God, ie. the mind truly changes and subsequent deeds then prove it (deeds worthy of repentance Act 26:20).
Thus we can see the seriousness of a willful transgression from a state of having been cleansed (Heb 10:22 and 29) whereby one also possesses a true knowledge of the light...
Heb 10:26 For if we sin wilfully after that we have received the
knowledge of the truth, there remaineth no more sacrifice for sins,
The sin/repent/sin/repent cycle that many theologies imply lacks any conception of the true deceptive nature of sin. It treats willful sin in a light manner. Yet Peter warned us...
2Pe 2:20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.
2Pe 2:21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.
A second repentance after an authentic salvation experience is not something one ought to take for granted. It is one thing to sin when in a state of darkness (the state of sinners) but it is quite another to sin from a state of full knowledge, having actually been cleansed by the blood of Christ and having been raised from darkness to light.