Lyric discussion by donkeykong325 

Cover art for Giants lyrics by Five Iron Frenzy

I think that this song is talking about how money and the strong desire of it is destroying Christianity and simple freedoms of people. It is talking about how no one is noticing (When no one looks the clouds come rolling in) that big business is taking over small business and pushing God out of thte picture completely (See the rest of the first verse).

The second verse is elaborating on how big businesses are pushing out small businesses and thus, taking away the people's freedoms (Oh don't you cry for the mom and pops,/Nothing but dry eyes for integrity's demise.) The integrity's demise part is saying that big businesses are corrupt and taking away our liberty to choose our own businesses.

Corporate Darwinism is not saying that businesses are anti-Christian specifically. It's talking about survival of the fittest and the strong survive (i.e. the big businesses thrive while the small ones die).

Adam Smith is basically the man who invented American economics. To say "This house is haunted by the ghost of Adam Smith" is to say that everything in the economy reflects him.

Bottom line, this song is about how big businesses are pushing God outu of our society with their corruption and lust for money and worldy possessions. Meanwhile, no one notices and those who do notice don't care or do anything about it.