To be forgiven and to be justified are two very different things. To be forgiven means that you actually did something wrong and that wrong was overlooked. To be justified on the other hand means you did nothing wrong and therefore, you’re not guilty!
If you’re in Christ, then you’re justified; He’s given you a new life that has never existed before. Don’t ever be weighed down by all those wrongs you may have done in the past because in Christ, your slate is clean!
Actually, Justification is the result of Jesus' death on the cross. The apostle Paul made it perfectly clear when he said "we have now been justified by his blood" (Romans 5:9).
Also, I'm not quite sure the forgiveness/justification distinction works, since our being forgiven by God is thoroughly bound up with our being legally declared righteous by the Almighty Judge. Remember, when we are justified, it means our debt of sin is imputed on to Christ on the cross (Colossians 2:14), and His righteousness is imputed on to us (Philippians 1:11 and 3:1).