God's view of man: Do we have a problem?

Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.  Professing themselves to be wise, they became fools, and changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and fourfooted beasts, and creeping things.  Romans 1: 21-23 (KJV)

Breaking this down into logic flow:

Precondition:  'they' knew God
If 'they' do not: (glorify God as God) and (be thankful to God)
Instead: ('they' are vain in their imaginations) and ('they' have dark hearts)
Then: 'they' (claim to be wise, but are fools) and (reduce God to the same level as they are or even lower)

How do you see God? 
Why would you 'exalt' or 'glorify' Him? 
Why would you thank Him? 
What has He done for you?