What is the theme in Manual of the Warrior of Light by Paulo Coelho?

Another theme is continuous training. A Warrior of the Light is continuously training and working to be a better Warrior. The more he trains, the better he will become and the easier it will be for him to stay on the path to virtue. There are several instances when a Warrior is confronted by hardship and a desire to quit his path. Evil can influence him, making him want to desert the life that he has lead and stray from his path. Angels, who give him strength to continue training and to stay on his path, often counsel him.