This is a collection of letters written by a Carmelite monk and the recollections of some of his speakings in the 1600's. It is a bit repetitive, but I guess the idea was important to him.
How do you get and stay in the presence of God? Practice, of course. How do you practice? Think about God. Read about God. Talk about God. Pray to God. Constantly strive to include God in everything. His presence in your life will become habit. :-)
This is no "All of Grace". OK, but no revelation from this one.