So agree with the above comment as well! I will add my own by recommending Dr. Keller’s book on Prayer. This has enriched my own studies and prayerful meditation on scripture. I am particularly fond of Luther’s approach to prayer and am journaling my responses to his four garlands.

I have now listened to a number of Dr Keller's podcast sermons. I have never failed to get a huge amount from each one. Some of my understandings and attitudes have been radically changed or enriched. I would recommend them to anyone whether convinced believer, struggling doubters or hungry searcher. I started with the podcast "and he kissed him" on the recommendation of my daughter. It's a good place to start, but every one is well worth listening to.