I'm good because I'm saved. If I'm not good I'm not really saved? Those who are saved can theoretically do whatever they want and not affect their savedness, but don't because...Why? Because they love God so much now that they're saved that they don't?
In which case why do saved people ever sin at all? Or do they?
Entirely too convenient, and verging on the tautological.
Correct!
Those who are saved can theoretically do whatever they want and not affect their savedness, but don't because...Why? Because they love God so much now that they're saved that they don't?
No, because God has specifically promised to make us good. I'll let Augustine explain it to you:
“Can you say, ‘We will first walk in His righteousness, and will observe His judgments, and will act in a worthy way, so that He will give His grace to us’? But what good would you evil people do? And how would you do those good things, unless you were yourselves good? But Who causes people to be good? Only He Who said, ‘And I will visit them to make them good,’ and, ‘I will put my Spirit within you, and will cause you to walk in my righteousness, and to observe my judgments, and do them’ (Ezek.36:27). Are you asleep? Can’t you hear Him saying, ‘I will cause you to walk, I will make you to observe,’ lastly, ‘I will make you to do’? Really, are you still puffing yourselves up? We walk, true enough, and we observe, and we do; but it is God Who He makes us to walk, to observe, to do. This is the grace of God making us good; this is His mercy going before us.” Augustine - Against Two Letters of the Pelagians, 4:15
Also Isiah 64:6 “But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.”
Our pretend rightesnous doesn't compare to God's standard anyways.