What God will accomplish in the life of an individual, a spiritual leader, a church, and the work of God is proportional to the place that will be given to prayer.
Neglecting prayer is an unspeakable tragedy. Admonishing against neglecting prayer and exhorting to a life of prayer is the main burden that the author wants to communicate to his readers.
If you want to become a person of consequence, see radical conversions to Christ, transformation in your children, change in your sheep, your church burning for God and His cause, and the work that God entrusted to you prospering, this book is your need of the hour.
Read it.