How has this thread gotten so off track? haha..
For starters, Christians can not be Jewish. You are born Jewish. To convert would mean you would become a Christian. And if not then you are denying that Christ is the Son of God so you would become a Muslim or something completely different.
Secondly, as Christians we are born into bodange with sin. The commandements are there for us to keep to, so we don't fall into sin and we please God. However because we do, (and God is so merciful, magnificent and graceful) Christ Jesus died on the cross setting us free from the law. Not to say we shouldn't stick to it. Even Christ gave us a new commandement! But, the law is the Old Testament. Christ Jesus is the New.
Like a Father who forgives his child endless times and then disciplines them, so our Father In Heaven forgives us if we turn to Christ Jesus and beg for repentance. Not to say that doesn't mean God The Father will discipline us later on haha.
God bless x