Good... so you're not confused about everything.
Shame on those people, I'm glad that I'm not one of them.
Please feel free to show even a single quote from me that would give you that impression that I believe that believers should just keep on sinning.
Rom 6:15 (KJV)
(6:15) What then? shall we sin, because we are not under the law, but under grace? God forbid.
Your problem is that you think that everything that God ever told ANYONE to do is for YOU to do.
God separated Israel for a purpose and gave THEM things to do that do not apply to the body of Christ. It's just that simple.