Hiya, Bigmac!
I read your offer of a debate and I might have some time later next week. I've been incredibly busy with work and family issues atm. But real quick, as I'm pressed for time even now, let me give some clarity to my statements.
As far as a Christian sinning all they want and continuing to be saved...
You, I, and every other believer already do this. So I really don't see what the issue here is. We sin every day either by thought, word, or deed. We sin even more than we are aware, as God's requires absolute perfection to be saved. Salvation is a gift via grace - God's unmerited favor. To add a single requirement to it negates it as such. It turns salvation into a merit based system. How many works are needed? How many sins will cause one to lose it? Nobody ever has the specifics.
And once again: Christians should live a life that is pleasing to the Lord. Absolutely. 100% true. But we don't. No one does. When we disobey, we invite God's chastisement into our lives. But that chastisement never involves the loss of salvation. 1 Corinthians 3:15 teaches this. Righteousness is imputed without any works needed before or after salvation. (Romans 4:5-6).
God's chastisements can bring a loss of joy, deep sorrow and grief, or sickness.
But, if the believer will not turn from his wickedness, God's chastisement can even lead to an early death:
"To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus." (1 Corinthians 5:5).
But the believer remains saved.
Now, as far as a Christian who stops believing, yet still remains saved:
If it were not so, than salvation, yet again, would cease to be a gift, and instead becomes an obligation. And the questions that need to be asked would be:
"How long could one stop believing before salvation is lost - a second, a minute, an hour, or a day?"
"If one stops believing and salvation is lost, yet begins to believe again, is salvation regained? If so, how many gains/loses of salvation will God allow?"
"If one stops believing in a moment of anger, loss, sickness, or grief, does God overlook those?"
Simply: Salvation is either a gift with no strings attached, or it's not. It's either all of grace, or it's a mixture of faith and works. If works play no part, God gets all the glory and credit for our salvation. If works play any part, we can share in God's glory and have the right to boast.
I wish I had more time to get to all of your posts, but I'm absolutely pressed. I will try my best to set up a debate with you. Again, hopefully later next week.