What is meant by "making the will sincere" is that one should not deceive oneself. This sincerity should be like the sincerity with which we dislike a bad smell or love what is beautiful. This is called satisfying your own conscience. Therefore a Jedi is watchful over himself even when he is alone.
People usually lose their sense of judgment toward those whom they love, toward those whom they despise or dislike, toward those whom they fear, toward those whom they pity and towards those whom they pamper or are proud of. Therefore, there are few people in this world who can see the bad in those whom they like and see the good in those whom they dislike. As Jedi we seek to overcome these habits in ourselves. Thus seeing the truth in all people.
A Jedi first searches himself before he demands it of others, and makes sure first that he himself is not a transgressor before he finds transgressions in others.
Jedi should try to avoid completely four things: Arbitrariness of opinion, dogmatism, narrow-mindedness and egotism.
It is difficult to see examples of true Jedi. Everybody errs a little on the side of his weakness. Therefore it is easy for others to point out the shortcomings of those who follow the Jedi way. Then it is to point out their good qualities.
Humility is near to moral discipline; simplicity of character is near to the Jedi Way; and loyalty is near to sincerity of heart. If a man will carefully cultivate these things in his conduct, he may still err a little, but he won't be far from the standard of the Jedi Way. For with humility or pious attitude, a man seldom commits errors; with sincerity of heart, a man is generally reliable; and with simplicity of character, he is usually generous. You will seldom make a mistake if you use these points to begin from.
A Jedi has no worry and no fear. For if he looks within himself and is sure that he has done right in all things, what does he have to fear or worry about?
A Jedi should be ashamed if his words are better then his actions.
If you have the insight to perceive a truth, but not the wisdom to keep to it, you will lose it again, though you have discovered it.
Steffan Karrde, Temple Councilor