Galatians takes a look at Paul’s thoughts on Jewish Law.
The fourth Epistle, and the ninth book in the New Testament, is Paul's letter to the Church in Galatia; Galatians. It was written around 49 AD and addressed Paul's concerns that some Christians were saying that Jewish Law must be observed. Paul opposed this and said in his letter that faith in Christ alone is the only requirement of being a Christian. He also warned of the terrible results of failure to believe in the pure Gospel of Christ.
Galatians 4:28-31
"Now we, brethren, as Isaac was, are the children of promise. But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman. So then, brethren, we are not children of the bondwoman, but of the free"