This Psalm is all about the  power of God at work in the lives of His people.  In this Psalm  of praise it says that God’s enemies will be scattered and that they  will be blown away like smoke, and they will melt like wax before a  fire (Vv. 1, 2) .  That is extremely powerful imagery.  Nothing and no  one can stand against God.  For us that includes anything that  stands in the way of walking forward in the victory which the Lord  intends  for us to have.  Our problems, our fears, worries, failures, will  fall powerless in the presence of Almighty God.  He is greater  and more powerful than any problem we will ever face.  Whatever  we are facing, rest assured that God can handle it and He can take care  of it.  This is where faith comes in; we trust God no matter what,  look to Him, and stand firmly upon Him – Christ Jesus our rock,  our fortress, and our deliverer.
When we fail to look to God and  seek His strength in the trials we face then we are much like an ancient   warrior who steps onto a battlefield without proper weapons.  How long do you think he would  last in the heat of battle without shield, sword, helmet, breastplate,  and coverings for his arms and legs?  He would not last anytime at  all, for he would be utterly defenseless and at the mercy of his  enemies.   The power of God so stirs the heart and not only can we fight the  battles,  but we can lift our voices in praise to God as we do so.  “Sing  unto God all ye kingdoms of the earth.”  The call is to lift  our voices to God and exalt and praise His holy name.
Singing requires a certain  amount of energy doesn’t it?  A singer who leads in worship  and sings in a worship setting has to have energy and motivation to  do that.  The Holy Spirit provides exactly what is needed to accomplish  praise.