A born-again person can sin, and we do, but we do not
practice sin, that's the key word,
practice. Unfortunately some modern translations don't include that word, even the king james doesn't, but its there, and the NAS correctly renders it at least.
If I say I'm a practicing doctor, what comes to mind? That I regularly see patients, prescribe medicine, even perform operations right? If I'm a practicing sinner, I sin on the regular, in fact it defines my life and is my practice. Christians are sinners, but we are not practicing sinners. This is the correct understanding of 1 John and what it says about sin in the believers life.
The life of a Christian is not ever characterized by a continual, unrepentant practice of sin. We can fall into sins, and can fall into sinful lifestyles for a season, but we can't stay there. God disciplines those he loves, and he always will restore us.
As far as the love thing goes; we love God because he saved us, we don't love God to get saved. When we get saved, which is through repentance and faith in Christ, we have the love of God shed abroad in our hearts and we love him because of his amazing grace and mercy which he has shown us.
Our fruits also stem from this love which we have for God, both the fruit of the Holy Spirit as described in Galatians 5, and the works that flow from these fruits. Faith alone saves us, but if we truly believe the gospel, then we cannot help but love God for his great and tender mercy!
He is speaking of those like judas who saw God and the truth and saw salvation however turned away from it, these are the people in Heb 6. Not Children of God turning from faith. They were never saved. Also they are those who Jesus said a pig returns to the mud.
On this point we absolutely agree.
The moment you are truly saved, you have eternal life, you are absolutely guaranteed heaven and you shall never perish. From that glorious moment onward you are forever free in Christ, and yes, regardless of your performance. Though you will certainly be a new person.