Christianity seem to be one of the most heavily influenced religions by politics and business today (http://redsonja2000.blogspot.com/2006/06/corruption-of-christianity_20.html). What is your perspective?

I agree! there is lots of money in religion. Wanna start a church with me? we can teach eternal damnation of the soul if you don't pay for our mansions and cars :P

That's politics.
Any (insert any groups of mass) reaches significant number of voters, politics come to play.

Religion was used as a political tool way back when, it is not surprising that there is a link between modern politics and organized religion.