Watts' text is a strong Christological interpretation of Psalm 72. We sing of the worldwide reign of Christ (st. 1), who is praised by all creatures (st. 2 and 5) , and whose rule results in blessings on people "of every tongue" (st. 3) and redemption for the outcasts (st. 4). The text has a strong missionary focus.
Psalter Hymnal Handbook
The confessions make it clear that the ascension of Christ opened the door to the rule of his kingdom. This fact is comforting to those who love him and is a fearful threat to those who despise him. The response therefore is praise and adoration from people of faith, and resistance from those who reject him.
Our World Belongs to God, paragraph 27 affirms “All authority, glory and sovereign power are given to him,” and reaffirms it in paragraph 43: “Jesus Christ rules over all.”
Consider the clear affirmation made in Heidelberg Catechism, Lord’s Day 19, Question and Answer 50: “Christ ascended to heaven to show there that he is the head of his church, the one through whom the Father rules all things.”
It is no wonder that those who despise him join together to conspire against him, for Christ’s aim as Lord is to “destroy the devil’s work…every force which revolts against you and every conspiracy against your holy word” (Heidelberg Catechism, Lord’s Day 48, Question and Answer 123).