Have you ever considered that if our salvation is dependent on keeping the Law, then we might as well be Jewish? And if our salvation is dependent on keeping the Law then Jesus died on that cross for nothing! Every time we make assumptions on someone’s salvation based on what Mosaic law they are breaking, we are telling Jesus that his sacrifice means nothing to us.
Because Jesus went to the cross, because he suffered the degradation and humiliation of the cross to be a sacrifice for any sin I have ever or will ever commit, I have freedom.
Sin still matters, but it matters because it prevents us from enjoying the relationship with God that he wants to have with us. But because Jesus left all of my sins in that tomb, I have the freedom to stand before God as His child.