The law and the gospel are not separated, rather their relationship is vital: the law send us to Christ and the gospel returns us to the law for our sanctification. The believers to which Paul wrote, were in disagreement with one another on peripheral issues, not on issues central to the faith. So Paul tells them to accept one another in Christ and therefore, differentiate between that which is cultural, traditional, and denominational. Failure to do this will lead to one of two extremes with Christian freedom.
topic: Christian Thinking