Nor does it mean you won't suffer some in this body from them. But it means that none of those things can hurt you eternally. You are secure from your sins. My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous.
Christians ought to quit their sins.
But we are not perfect. You are Settled in heaven. That verse is all written in the presnt tense. It does not say that we will some day sit together with Christ. It says we are already sitting together in heavenly places in Christ.