When a soul sets out upon this path He [Jesus Christ] does not reveal Himself to it, lest it should feel dismayed that its littleness can contain such greatness, but gradually He enlarges it to the extent requisite for what He has set within it...  The important point is that we should be absolutely resolved to give it [our soul] to Him for His own and should empty it so that He may take out and put in just what He likes, as He would with something of His own... as He refuses to force our will, He takes what we give Him but does not give Himself wholly until He sees that we are giving ourselves wholly to Him.
St. Teresa of Jesus ~ Way of Perfection Ch. 29