Bone of His Bone by Frederick Huegel and published by Classics.
One thing for the missionary is inevitable. If he is to go forward in the face of
the seemingly insuperable obstacles which beset him, ushering in a new day for enslaved souls, if, I repeat, he is to do the thing which God expects of
him, and the Church expects of
him, and what the heart-rending need of these to whom He has come as an ambassador of
light requires of him, then he must himself appropriate in an ever-deeper and fuller way the power of Christ. He must himself
be bound to that unconquerable Christ who all down the centuries has through His disciples achieved the impossible. He must get beyond a mere intellectual knowledge of the historical Christ, and so entwine the tendrils of
his spiritual nature in the Eternal Christ that he imbibes a divine life.