With Christ in the School of Prayer by Andrew Murray

This is a classic book about prayer. One hundred years after he went Home, Murray's book still is relevant for the children of God. 

"Of all the traits of a life like Christ, there is none higher and more glorious than conformity to Him in the work that now engages Him without ceasing in the Father's presence: His all-powerful intercession. The more we abide in Him and grow to be ike Him, the more His priestly life will work in us. Our lives will become what His is - a life that continuously prays..."