This collection of articles by Srila Prabhupada from Back to Godhead magazine covers knowledge of the soul and the practice of bhakti-yoga. These interviews, lectures, and essays cover topics such as the goal of human life, seeking a true spiritual teacher, reincarnation, super-consciousness, Krishna and Christ, and spiritual solutions to today's social and economic problems.
 
This is one of my favorite books. I can pick it up and randomly flip to any article and find deep meaning in it.