How can we practice obedience if we are simple in knowledge?

An atheist employer had a very simple and God-loving house-servant, who would not cease to bear witness to the Lord Christ in the spirit of simplicity. One day the master wanted to mock him. He called him and asked him, “Are you a preacher, Sam?” The slave answered him, “I love my Lord Jesus Christ, and I would like everyone to enjoy His love.” The master asked him, “If you are an evangelist, you must know the meanings of the Bible. Tell me what the meaning of this phrase is: “For whom He foreknew, He also predestined to be conformed to the image of His Son” (Rom. 8:29). In simplicity the servant asked him, “Where is this verse, sir?” The master answered him, “In the Epistle of Paul the Apostle to the Romans.” Then in simplicity the servant replied, “Dear sir, I will explain this phrase to you very simply. You need to begin with the Gospel of Matthew. And when you carry out everything that our beloved Christ commanded in this Gospel, then start with the Gospel of Mark and do everything that the beloved Lord commanded us in this Gospel. Then the Gospel of Luke and obey all the commandments of the Lord contained in that Gospel. Then the Gospel of John, the Acts of the Apostles, and by the time you get to the Epistle to the Romans, you will find its meaning quite clear and very easy to understand.”