Who gets to define what it means to keep God's commandments?

 Q: Who gets to define what it means to keep God's commandments?

A: Jesus defined what it meant to obey the commandments when he was asked which was the greatest commandment. He said if we will love God with all our strength and being and love our neighbor as ourselves, then we will have fulfilled all the Law and all the prophets. 

Paul said the same thing when he wrote that all the Law and all the prophets were briefly comprehended in this one saying, and then he quoted Jesus on it. 

That doesn't mean we don't diligently apply ourselves to learning as much about our Creator and his ways as possible. I believe that begins with prayerfully reading his Word on a daily basis. I recommend reading every day, always picking up today where we left off yesterday.