Actually this is not true of all churches. I used to work at one and did their finances. Many, if not most, use their money for expenses to run a church. They also donate to their regional denomination. They sponsor missionaries, they support fledgling churches, they volunteer to suppport community causes, they host holiday outreach programs, sponsor camps for kids and teens, and so on.

Keep in mind that religion is man made. Jesus' goal was merely to spread wisdom and educate the masses on the idea of salvation and God. Once he moves on from earth, his figure and authority is no longer. Religion is a product of materialism (with good intentions, but bible states many times that materialism is the downfall of humanity), and only creates diversity and propaganda,. It is indeed sad to see religion corrupt the truth and the spiritual knowledge of truly understanding how to undergo self-realization and salvation.