“He turned the sea into dry land; they passed through the river on foot. There did we rejoice in him, who rules by his might forever, whose eyes keep watch on the nations – let not the rebellious exalt themselves. Selah” – Psalm 66:6-7
The psalmist accounts the miracles of crossing the Red Sea and then the crossing of the Jordan 40-years later. The exodus of the Jews from Egypt and the care of the Jews for the next generation resulted in great praise and worship of Yahweh. The crossing of the Red Sea was both an incredible display of God’s power and his love for his elect.
Throughout Scripture God demonstrates his love for the nations and his desire to reach them and call them to himself. The truth is, God has called some to have a relationship with him and others to spend eternity in hell. Not all nations, nor the individuals within, will worship the Lord. James Montgomery Boice said, “The call to the earth to praise God in verses 1–7 is a proper kind of universalism, meaning that God is God of the whole earth and that all the peoples of the earth should acknowledge him as God and be thankful. But the fact that the peoples of the earth must be invited to “come and see what God has done” betrays the reality of the situation; although people ought to praise God and be thankful, they actually do not do it.” Those who have been called are destined for an eternity with the Lord. Those who have not been called are warned to not rebel against God’s plan for his elect.
Those who are not elect in the Lord still live by his blessings and provisions, but they are warned to not live contrary to God’s will for his people. God watches over the nations, both those for him and those against. If the rebellious interfere with God’s plan or molests God’s disciples, they will be dealt with accordingly. The rebellious nations have been warned and are being monitored. The enemies of God’s glory and oppressors of his elect will suffer at his hand.
 James Montgomery Boice, Psalms 42–106: An Expositional Commentary (Grand Rapids, MI: Baker Books, 2005), 538.