Once saved always saved? Or once saved, always repent?
Apostle John’s words
[ 5 This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all. 6 If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth. 7 But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make Him a liar, and His word is not in us. 1 John 1:5-10 ]
[ 5 This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all. 6 If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth. 7 But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make Him a liar, and His word is not in us. 1 John 1:5-10 ]
Is walking in the light = walking perfectly Sinless life? If that is so, the John is contradicting himself when he say, IF you walk in the light... the blood of Jesus cleanses him. Hence John is not talking about living a "Sinless" life, but a repentant one. That's why in 1 John 1:9, he says IF you confess (repent) your sins, he is faithful righteous to forgive us. So if walking in the Light = Sin and repent, then walking in darkness is Sin and don't repent. THAT, is how john arrives at this conclusion :
[ My little children, these things I write to you, so that you MAY NOT SIN. And IF ANYONE SINS, we have an Advocate with the Father, Jesus Christ the righteous. 2 And He Himself is the propitiation for our sins, and not for ours only but also for the whole world. - 1 John 2:1 ]
John is referring to those who walk in the light, who Sins and Repent.
Apostle Paul’s words
[ 22 For I delight in the law of God according to the inward man. 23 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members. 24 O wretched man that I am! Who will deliver me from this body of death? 25 I thank God—through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin. - Romans 7:22-25 ]
This is the same as Paul, who explains how he DELIGHTS IN THE LAW OF GOD, but knows that there is a Law of Sin in him that prevents him from being saved. Therefore he thank God for Jesus Christ, because through Christ atonement for his Sins, he can now SERVE THE LAW OF GOD WITH HIS MIND and not get condemned under the atonement. This is how he arrives at this THEREFORE THERE IS NOW NO CONDEMNATION...
[ There is therefore now no condemnation to those who are in Christ Jesus,[a] who do not walk according to the flesh, but according to the Spirit. - Rom 8:1 ]
And notice, the gift of no condemnation is given to who? Those "who do not walk according to the flesh (earthly, carnal desires), but according to the Spirit (heavenly, righteous desires)"
Both Paul and John, are speaking harmoniously with each other.