Christ died once and for all sin for truly if you believe in Christ your sins are forgiven and if they are forgiven, there is no longer any need for sacrifice. Neither was sacrifice ever meant to take away sins. It only served as a reminder of sin. Neither was sacrifice something God desired, rather he desires us to act justly, love mercy, and walk humbly with our God. To confuse the Law with Salvation is the same as confusing a map of the world with the world itself. It is simply a pointer towards God and the grace that he offers. The law is only a shadow of the good things to come.
But notice, Christ died for the forgiveness of sins, not to prevent anyone from sinning. Forgiveness (and I mean true forgiveness) and reconciliation are only possible when the offending party admits their wrongdoing and asks for forgiveness. That is the purpose of the law, so that we might know our sins and confess them. But in Christ, no sooner does the confession leave our lips and the Spirit of repentance floods into our hearts does Christ forgive us of our sins. This is grace which redeems and overflows. We need only to turn back to him.