The Pharisees and Sadducees thought they had right and wrong all figured out too.
I'm also guessing people don't really believe Paul when he says nothing can take you out of god's hands and that instead of saying "now is there no condemnation" Paul really meant to write "now is there mostly no condemnation."
Ultimately God is the only one who can make this clear. None of us will ever be sinless as long as we are human. I do believe my sins are covered. I do not think that believing in Jesus is a get out of jail free card, where we can merrily sin up a storm (knowingly, willingly and unrepentently) and still receive salvation.
I choose to do the best I can, each day that I can. The Lord will sort out the rest.