Don't forget the rest of the epistle...
1Jn 2:3 And by this we know that we have come to know him, if we keep his commandments.
1Jn 2:4 Whoever says "I know him" but does not keep his commandments is a liar, and the truth is not in him,
The simple truth is as believers, we have been given a new heart; we are indwelled by the Holy Spirit, and these things affect everything that we do. Anyone who can wake up, and say "Today I sin!" does not know Christ, and is not saved.
While I agree that there is a definite possibility that a person who wakes up one morning and makes a commitment to sin is not saved.
However, only God knows the heart and we CAN grieve and quench the Holy Spirit which indwells us as believers. We need a balanced approach.
If one of God's children willingly commits sin there is a consequence:
Revelation 2
20 Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols.
21 And I gave her space to repent of her fornication; and she repented not.
22 Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds.
23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.
Sin in the Christian requires chastisement then repentance or it's consequence - physical death.
Revelation 3:19 As many as I love, I rebuke and chasten: be zealous therefore, and repent.
Romans 8:13 For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live.
If neither is the outcome then as Hebrews 12:8 indicates that person is not a child of God.
But sin does happen in our assemblies and is happening more and more in these last days as the spirit of Jezebel works in our churches.
IMO, You are right to warn but not to summarily condemn.
The point is that we are not to be white robed pharisees:
Luke 18:11 The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican.
but white robed physicians to our sinning brethren:
Mercy first then judgment (to be left to God).
James 5
19 Brethren, if any of you do err from the truth, and one convert him;
20 Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins.
James 4
11 Speak not evil one of another, brethren. He that speaketh evil of his brother, and judgeth his brother, speaketh evil of the law, and judgeth the law: but if thou judge the law, thou art not a doer of the law, but a judge.
12 There is one lawgiver, who is able to save and to destroy: who art thou that judgest another?
Obviously, after the counsel of the brethren and the church with no positive result the erring one is to be put out of the assembly to protect the Body of Christ and to shame him/her into a change of mind.
Brother Havensdad FWIW, I believe you to have a heart for the church(es) but need a little compassion in the direction of rescuing those who stray or are unregenerate in our churches.
Perhaps you have that compassion but it doesn't show by your posts.
With God if all things are possible, He can transform tares into wheat and use us as His instruments.
HankD