BCS,
2 Peter 1:9 only speaks of past sins. Not future sins. I know that Trinitarian Baptists, and Presbyterians like to throw in the word future. But, as you partially quoted
1 John 3, it does say he who sins is of the devil. Future sins isn’t even in the equation. You are to repent. Leave the sinning behind. Then follow Christ. To go back to sinning is a dog returning to eat its vomit.