Hezekiah was one of the "good kings" of the period of divided kings. He upheld what the Divine Principle refers to as the "ideal of the Temple." If the people of Judah and Israel had united under that ideal, the Messiah could have come at the end of the period of divided kingdoms, rather than nearly 600 years later.
The story of Hezekiah also speaks to the Unificationist concept of lineage. Although the kings of Judah all carried forth the Davidic physical lineage, by no means did they all inherit David's spiritual tradition. Hezekiah's father, Ahaz, was one of Judah's most wicked kings, who even sacrificed one of his sons to the Moabite god Chemosh. It is possible that Hezekiah witnessed this horrid spectacle and that this traumatic experience helped form his revulsion toward Canaanite religion and his passionate devotion to Yahweh, a god whose prophets spoke out against such practices as human sacrifice.
Yet, Hezekiah failed to pass on his religious attitude to his own son, Manasseh, who reverted to the evil practices of his grandfather. Hezekiah's shortsightedness on the question of lineage is shown in his response to Isaiah's prophecy that Hezekiah's descendants would be taken captive to Babylon. Instead of becoming concerned about this dire prophecy and seeing what he could do to prevent it, Hezekiah said, displaying a short-term attitude centering only on his own reign and not that of his descendants:
"The word of the Lord you have spoken is good," Hezekiah replied. For he thought, "Will there not be peace and security in my lifetime?" (2 Kings 20:19)
Earlier, Hezekiah had caused Isaiah to withdraw his prediction of Hezekiah's own death when the king prayed in tears and implored God to change his destiny. If he had adopted a similar attitude when Isaiah predicted the Babylonian exile of Hezekiah's descendants, history might have taken a dramatically different turn.