"In another letter written on Christmas Eve of 1754, the saint wrote,

The better and more perfect manner of celebrating Christmas consists therein, to strip away any joy of the senses, in order to take all your pleasure in the accomplishment of the divine good pleasure.  The entire and most holy life of Jesus was all cross . . . you have enough reason to be still more joyful than before, because now you are more hidden in Jesus Christ upon the cross . . . Therefore, feed yourself upon the divine will in the greatest poverty of spirit and in naked solitude, and be sure that , in this way, you will – in your interior – provide a living retreat for the heavenly Bridegroom. ~Paul of the Cross' letter to Columbia Gertrude Gondalfi (16th letter on December 24, 1754 in Vol.  2 on Page 425 for Paul's Letter 930) 

It may at first sound like an exaggeration when the saint states that “the whole life of Jesus was a cross”.  When, however, one takes into consideration that Paul saw love and sorrow so closely united that, for him, the passion of Jesus was a manifestation of the love of God, then this assertion in terms of its content is very close to another one of Paul’s statements:  “The entire life of Jesus was love”.  The experienced director of souls then exhorted his correspondent, a religious Sister, “to strip off any joy of the senses”.  Nonetheless, this renunciation was not a goal in itself but only a means of helping her experience a greater, purer, and deeper joy – that inner joy a person experiences when completely fulfilling God’s will.  In this way one becomes totally “hidden in Jesus Christ upon the cross”,  a “living retreat” provided for the “heavenly Bridegroom” in one’s own interior." ~taken from Chapter 5 of The Mysticism of the Passion in St. Paul of the Cross by Martin Bialas, CP