Many forms of mystical experience involve a conviction of unity with the divine or with 'divine Nature', resulting in a sacred compassion for all beings. Observe this almost Buddhistic, if not Franciscan, love in Isaac of Syria (Isaac of Ninevah):

= = = = = = = = = = = = = = = = = = = = = = = = = = =

    What is a charitable heart?

    It is a heart which is burning with charity for the whole of 
creation,

   for men and women
   for the birds, for the beasts;
   for the demons

  - for all creatures.

   Whosoever has such a heart
      cannot see,
      or call to mind,
      a creature 
   without eyes filling with tears
     by reason of the immense compassion 
     which seizes the heart

   That is why such a one
      never ceases to pray also
      
      for the animals
      for the enemies of truth
      for those who do one evil

   Moved by the infinite pity
     which reigns 
     in the hearts>
     of those
     who are becoming united with God.