1) Permanence 2) Permanency 3) Perpetuity 1) Perpetuity 
• (n.) Future duration without end; the relation or state of being sempiternal.
Sem`pi·ter'ni·ty noun [ Latin sempiternitas .] Future duration without end; the relation or state of being sempiternal. Sir M. Hale. 
(Lat. semper, always) Eternity conceived as everlasting existence or perpetuity. May have a beginning, but no end; an end, but no beginning; neither a beginning not end. -- R.B.W.