Lawlessness means to be outside of the law of the Spirit of life or the law of spirituality. Rom. 6:19; Rom. 8:2-4.
“I am speaking in human terms because of the weakness of your flesh. For just as you presented your members as slaves to impurity and to lawlessness, resulting in further lawlessness, so now present your members as slaves to righteousness, resulting in sanctification.” (Romans 6:19, NASB)
“For the law of the Spirit of life in Christ Jesus has set you free from the law of sin and of death. For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit.” (Romans 8:2-4, NASB)
In Romans 8:2-4, “the Law” refers to the Mosaic Law, “flesh” refers to the old sin nature, “for sin” means for a sin offering, “condemned sin” refers to the old sin nature, and “requirement of the law” refers to the Mosaic Law that it might be fulfilled through the filling of the Holy Spirit. The believer out of fellowship removes themselves from the law of spirituality. 1 John 3:4 is dealing with the law of spirituality, not the Mosaic Law.
“Everyone who practices sin also practices lawlessness; and sin is lawlessness.” (1 John 3:4, NASB)
Sin is not defined here as the transgression of the Mosaic Law because sin was in the world before the Mosaic Law. Rom. 5:13-14.
“for until the Law sin was in the world, but sin is not imputed when there is no law. Nevertheless death reigned from Adam until Moses, even over those who had not sinned in the likeness of the offense of Adam, who is a type of Him who was to come.” (Romans 5:13-14, NASB)
The carnal Church Age believer is operating outside of the law of spirituality, therefore the carnal believer is described as lawless. Spirituality in the Old Testament was the faith-rest life. Rom. 14:23.
“But he who doubts is condemned if he eats, because his eating is not from faith; and whatever is not from faith is sin.” (Romans 14:23, NASB)
The believer under control of the old sin nature does lawlessness. This is the same as walking in darkness. Just as darkness and light are exclusive, light is a synonym for the edification complex of the soul filled with epignosis Bible doctrine. “Darkness” emphasizes ignorance of Bible doctrine. 1 John 1:6; 1 John 2:11.
“If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth;” (1 John 1:6, NASB)
“But the one who hates his brother is in the darkness and walks in the darkness, and does not know where he is going because the darkness has blinded his eyes.” (1 John 2:11, NASB)
Therefore, the carnal believer walking in darkness can only imitate the unbeliever and cannot imitate God as commanded in Ephesians 5:1-2. 1 Cor. 3:3.
“Therefore be imitators of God, as beloved children; and walk in love, just as Christ also loved you and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma.” (Ephesians 5:1-2, NASB)
“for you are still fleshly. For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men?” (1 Corinthians 3:3, NASB)
The believer who sins after salvation gets out of fellowship through their own volition. This decision to sin puts them outside of God's intended way of living with maximum time filled with the Holy Spirit. The believer who denies the operation of the old sin nature or personal sin after salvation is disciplined by God for their disobedience. The carnal believer who denies the need to confess their sins to God the Father and thereby be restored to the filling of the Holy Spirit is disciplined by God for their disobedience so they will realize their need to confess their sins and return to fellowship with God. 1 John 1:8-9.
“If we say that we have no sin, we are deceiving ourselves and the truth is not in us. If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness.” (1 John 1:8-9, NASB)
Spirituality and carnality are mutually exclusive. Either the Holy Spirit will control the believer’s soul or the old sin nature will. There is no such thing as partial spirituality. Any sin in the Christian life results in lawlessness and excludes the Holy Spirit, grieving or quenching Him.