Is it ensure, insure, or assure?
early 15c., "supreme happiness," from Middle French béatitude (15c.) and directly from Latin beatitudinem (nominative beatitudo) "state of blessedness," from past participle stem of beare "make happy," related to bene-. As "a declaration of blessedness" (usually plural, beatitudes, especially in reference to the Sermon on the Mount) it is attested from 1520s.
(bee-at-uh-toohdz, bee-at-uh-tyoohdz) Eight sayings of Jesus at the beginning of the Sermon on the Mount. The word is from the Latin beatus, meaning “blessed,” and each of the Beatitudes begins with the word blessed. They include “Blessed are the meek, for they shall inherit the Earth” and “Blessed are the peacemakers, for they shall be called children of God.”