Jesus also said in Matthew 12:36-37 - "But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgement. For by thy words thou shalt be justified, and by thy words thou shalt be condemned."
So to me, of course Jesus already died for our sins, and we were forgiven 2,000 yrs. before we were even born, but at the same time, that doesn't give us the right to go out and do whatever we want to. Jesus says several times that it isn't what goes into the man, but what comes out that defiles us. So, while we are forgiven, Praise Jesus for that, we must also be accountable for what we do while here on earth. As Jesus said to Peter in Matthew 16:19 - "And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven."