Summary: I think what happens is that when someone hears the Gospel–that God so loved us, weak and sinful though we are, that He gave His only Son up to death, that this Son rose and wants to give us the same gift–there are only two possible responses.
THE AWESOMENESS AND NEARNESS OF GOD
The kingship of the LORD is awesome: it makes the people (or peoples) to “tremble” at His presence (Psalm 99:1). He is totally ‘other’ - dwelling between the cherubim, enthroned in heaven. He created all things, and even the earth “shakes” at his presence!
There is a correlation between the concept of the LORD dwelling “between the cherubim” (Psalm 99:1), and the LORD being great “in Zion” (Psalm 99:2). The ‘mercy seat’ in the Temple was adorned with cherubim. This awesome God - who is “high above all peoples” - has revealed Himself to Zion. It is therefore incumbent upon all peoples to acknowledge Him (Psalm 99:3).
Psalm 99 provides us with a threefold refrain: His name is holy (Psalm 99:3); He is holy (Psalm 99:5); the LORD our God is holy (Psalm 99:9). This is echoed throughout Scripture (Isaiah 6:3; Revelation 4:8). Yet the reign of the LORD is manifested not through the wielding of His power: but through the establishment of impartiality (Acts 10:34-35); justice (Genesis 18:25); and righteousness (Psalm 99:4).
In the Hebrew language the word for “holy” carries with it not only the meaning of ‘being set apart’ - but also the idea of betrothal. Thus the transcendence of God becomes immanent as he reveals Himself first to Zion (Psalm 99:2), and then through them to the peoples of the earth. The duty of God’s people has always been to “proclaim” the LORD, and “worship” at His footstool (Psalm 99:5).
Moses, Aaron and Samuel were priests who knew the joy of answered prayer (Psalm 99:6). We can have access to the living God, even today, when we make our approaches through the blood of Jesus.
He is “the God who forgives” - but still must take vengeance upon wrongdoing (Psalm 99:8). Our sins are avenged in the sacrifice of His ‘beloved Son’ (Luke 9:35) - and He purifies us through the blood of His Chosen. Thus He is ‘both just, and the justifier of all who have faith in Jesus’ (Romans 3:26).
Worshiping “in His holy hill” (Psalm 99:9) is synonymous with worshiping “at His footstool” (Psalm 99:5). Zion is both His footstool and His holy hill. Again we are reminded of our duty of proclamation and worship (Psalm 99:9).