Themes of Songs in the Bible

If you had to choose a theme for Psalm 104 it would most likely be creation. Verse 24 sums it up well, "O Lord, how manifold are your works!  In wisdom have you made them all; the earth is full of your creatures."  Then we come to the last verse of the Psalm - "Let sinners be consumed from the earth, and let the wicked be no more!  Bless the Lord, O my soul!  Praise the Lord!"  Why such a shift in focus?  If I didn't believe the Psalter was inspired I would think that it was inserted wrongly.  

I think the larger issue is that I am bothered by such language.  In my politically correct culture, it seems harsh to praise God for his judgement.  But this is what the Psalmist is calling us to do.  In fact the three great themes of songs in the bible are creation, judgement, and salvation (especially in the book of Revelation).  

When was the last time we sang a song rejoicing in God's righteous judgement on his enemies?  Revelation 19:1-2 says, "Hallelujah!  Salvation and glory and power belong to our God, for his judgements are true and just; for he has judged the great prostitute who corrupted the earth with her immorality and has avenged on her the blood of his servants."

If the church triumphant in heaven sings praises of God's righteous judgement how much more should the church militant here on earth.  Creation, judgement, and salvation - the major themes of songs in the bible should be the themes of our songs as well.