From the Rule of the Society of St. John the Evangelist, Chapter 18: The Daily Office
“But for the office to be truly a means of our transfiguration we must cooperate by continually renewing our inner attentiveness, laying aside again and again the preoccupations and daydreams that confuse and tie us down. This effort to keep our hearts open to Christ will be needed all our lives; it is a hidden dying to self day by day.”
Daily Office Anchor Society 
I liked something Rob Prehn said in this regard this morning. He said that he daily offers God all that he has and tries to be open to the possibility that God will actually want and take from him something precious – in the manner of Isaac’s potential sacrifice.