Please help me to understand the words that I "underline" below. Does it mean his want of (bad) knowledge. Taken from our text "The Fundamentals of Islamic Creed pg 123, paragraph 2". "Of course, sometimes a man feels the sickness of his HEART. But the bitter medicine coupled with a prolonged treatment is hard upon him. He prefers the disease of the heart over [to] the bitterness of the medicine. That is because its cure consists in suppressing the carnal desires. But that’s hard upon certain souls although there is nothing better than that for them. Sometimes the man begins a course, but gives up too soon because of "his want of knowledge" and lack of perseverance. His situation is similar to that of a man entering into a fearsome path leading to a place of security. He knows that if he persists he will end up in a secure place."

“Want of” something means: lack or deficiency of something.

Examples of usage:

A vote of want of confidence is justifiable in certain circumstances.

“You complain of want of time—you, with your boundless leisure!”

“No great man ever complains of want of opportunity.”

“To accuse others for one’s own misfortune is a sign of want of education.”

“Parents who never showed their love, complain of want of natural affection in their children; children who never showed their duty, complain of want of natural feeling in their parents...”

 And Allah knows best