The Collaborative International Dictionary of English v.0.48:

Blessedness \Bless"ed*ness\, n.
   The state of being blessed; happiness; felicity; bliss;
   heavenly joys; the favor of God.
   [1913 Webster]

         The assurance of a future blessedness.   --Tillotson.
   [1913 Webster]

   Single blessedness, the unmarried state. "Grows, lives, and
      dies in single blessedness." --Shak.
      [1913 Webster]

   Syn: Delight; beatitude; ecstasy. See Happiness.
        [1913 Webster]

WordNet (r) 3.0 (2006):

blessedness
    n 1: a state of supreme happiness [syn: blessedness,
         beatitude, beatification]