ANSWER: Lust is not a bad word in the Greek. It is often simple desire. It derives its evil meaning from the bad object to which it is "drawn out," which is a better translation than "drawn away." Lust has conceived when it moves the will to the evil purpose. The sin lies at this point, even before it becomes an outward act. (2) The thought of imagination of a sin is not sin, but rather it is the fuel of sin. It takes a volition to create a fire, a sin. It is the safest way to have in the mind as little fuel of sin as possible, to think as little as possible about the pleasure of sin. It is true that we cannot control the succession of our thoughts. But we can generally arrest the course of thought and turn it into another channel and keep the thinking of evil from becoming a habit. The adage is, "We cannot prevent birds fiying over our heads, but we can prevent their building their nests in our hair."
— Steele's Answers pp. 250, 251.