This one line in Galatians chapter five is the cause of much misunderstanding: “every man who lets himself be circumcised is obligated to keep the whole law” (verse 3). A historic interpretation is that if you do part of the law, you have to do it all. Since no one can do it all, you are, by participating in circumcision, engaging in a hopeless quest. An adjacent interpretation is that by “doing the law,” one engages in worthless practices because the sacrifices of the Old Testament cannot save.
These interpretations do not do justice to this text. Paul is dealing with people who believe that by accepting circumcision, festival observances, and dietary restrictions, that they are now “in” with God and nothing else need be done. Paul’s point is just the opposite. You cannot stop with these. You have to go on and do the whole law – which involves loving one another. The entirety of the law is summed up in this command: “Love your neighbor as your self.” Indeed, Paul’s point is not that Christians should not do the Law, but rather that they must keep it entirely! The law commands living by faith (Galatians 3:12). You must do that. The law commands loving and living in harmony with brethren (5:14). You must do that. You cannot pick and choose the commands and expect that God will owe you His blessing because you’ve done the things you find easy.