This is from the same author.
1Jn 2:1,2 My dear children, I am writing this to you so that you will not sin. But if anyone does sin, we have an advocate who pleads our case before the Father. He is Jesus Christ, the one who is truly righteous. 2 He himself is the sacrifice that atones for our sins—and not only our sins but the sins of all the world.
Indra, no one is advocating that a believer, who is born of God, continue in sin. We as believers do sin and we should not be surprised or shocked when that happens. When we were born again, God never removed the old sin nature from our body. That old sin nature, though crucified, still remains in the members of our body and we will not be rid of it until the redemption of our bodies takes place.
When we sin, Jesus Christ, who paid for that sin with His own blood, goes to the Father as our advocate and pleads our case, declaring that He (Christ) was already been judged and sentenced for that sin on the cross through death. That sin can not be judged again. So the believer, that sinned, will not be judged or dealt with according to his sin. God will be merciful and give him grace and if he receives that grace through humility, he will confess his sin before God and will be forgiven and cleansed from the unrighteousness of that sin / 1Jn 1:8-10.