No matter how skillful a teacher may be, if his/her only knowledge of a subject is what is written in the textbook, then that teacher will be greatly hindered in instructing any students in that topic. For example, a teacher may have thoroughly studied, and even memorized, an auto repair manual. But if that teacher had never done any auto repair at all, he would ge greatly limited in his ability to teach his students how to repair cars. The main thing that he could teach them would be how to study and get to know the text in the repair manual. But he would not be able to adequately teach his students how to repair the cars. When a student takes an auto repair class, his primary interest is (or should be) to learn how to repair automobiles. He doesn't take the class just to learn how to read, study, and take tests out of the repair manual.
The knowledge in the repair manual, or any book can only be correctly understood when the knowledge in the book is put into practice. There are many things that an instruction manual can't teach you, that can only be learned through actual experience. This applies just as much to someone wanting to live a godly life. He can read any number of holy books, he can put himself under a great Bible teacher, he can memorize hundreds of verses. But unless he is putting the knowledge into practice, he is not going to have any true understanding of what the text really means. For example, if he goes to goes to a dedicated and sincere "Bible believing" church, where the Bible is preached, taught, studied, memorized, and discussed, will he learn to put all those instructions into practice? Many Christians think that being a Christian (or being godly) means to study and learn what the Bible says.
True godliness (god-like-ness) consist of thining, behaving, and acting as a child of God. This means that we think and act like God. What does this mean? How does God act? God is Love (patient, kind, longsuffering, etc. (see 1 Corinthians 13). As His Children, we are to take on the character and nature of God, who is our Father.
In a very real sense, the best person to learn how to repair automobiles is an experienced auto mechanic. He can walk you through each part step by step. By actually getting your hands on the wrenches, screwdrivers, gauges, etc and repairing the motor, you have true learning. If you are studying the repair manuals at the same time you are working on the car, with the mechanic teaching and showing you how to do each part, your study of the manuals will gain much more meaning and reality.
The goal of any godly or religious training should not be to have our student be able pass written tests or to quote lots of Bible verses.