What Is the Meaning of Let God Arise

Psalms 68

1 Let God arise, let his enemies be scattered: let them also that hate him flee before him.

2 As smoke is driven away, so drive them away: as wax melteth before the fire, so let the wicked perish at the presence of God.

3 But let the righteous be glad; let them rejoice before God: yea, let them exceedingly rejoice.