Romans 6:7

‘For he who has died is justified from sin.'

And this is because, having positionally died with Christ (read in on the basis of the previous verses), we are ‘accounted as righteous' from sin. Sin has lost its power over us. Its penalty has been fully paid by Christ. As those who have died with Christ we are accounted as righteous through the gift of His righteousness (Romans 5:16). In consequence sin has lost its hold on us. It has to recognise that we are dead, and therefore freed from the penalty of sin. We are counted as righteous as far as the tyrant sin is concerned and as far as God is concerned.

Some, however, see these words as referring to Jesus Christ Himself (note the change from ‘we' to ‘he') Who, having died, was vindicated (seen as in the right) by His resurrection. On the other hand the change to ‘he' could just as well be indicating a kind of ‘off the cuff' comment by the writer.