It is clear that the Mormon Church made a strong effort to effect passage of Proposition Eight in the State of California. The Church has been criticized strongly for this by writers, bloggers (some of whom are also writers) and others.
No matter how one comes down on the gay marriage issue, and I think that people of good will can reasonably disagree on the matter, it is clear that the Church took an overtly political stance, and, by so doing, should lose its tax-exempt status forthwith.
If depriving gays of the right to marry is an infringement of civil rights, so too is judging persons on the basis of skin color. Therefore, the thousands of predominantly black churches that left their congregations with the clear impression that voting against Obama was a one-way express ticket to hell also took a political stand relating to civil rights, given Obama’s clear support of affirmative action programs. Those churches should also lose their tax-exempt status forthwith.
While we’re at it, why not do away with tax exemptions for religious organizations altogether? How did this weird notion get started anyway?
Mormonism is clearly a joke to any rational mind: the underwear, the tablets, all that stuff. But are those things any sillier than Catholics with their cannibal/vampire sacraments, devout Jews wearing Shirley Temple sausage curls, and Muslims [supply your own list—attach additional sheets if necessary]? I think not. Let’s give them all all the freedom they want to be ridiculous, but let’s also be super sure that not one cent of taxpayer money goes directly or indirectly to support them.

Salon.com
Comments
TAX THE CHURCH!!!!!!!
Many churches provide traditional community services and operate charitible programs that otherwise wouldn't exist. Their efforts in this regard entitle them to at least a partial exemption from taxation.
Others simply exist for the accumulation of wealth and the aggrandisement of their leaders. I've personally seen bags of $10k to $20k "love offerings" being used to purchase fine jewelry, cars, and Bacarat crystal figurines for the wife of a self-annointed "Bishop" at the quasi-cult "Chritian House of Prayer" (we call it the Chophouse) near Killeen, TX.
Let's let religious organizations follow the,"Render unto Caesar what's due Caesar" standard set in Romans. Good works? tax exempt. Spiritual efforts? Tax exempt. Elaborate temples, slush funds for ex-pastors (yes, Jerimaih Wright, I'm looking at you), political contributions or exhortations from the pulpit? Tax `em into the ground.
That's HARSH.
There should be no tax benefit to organizing under "whatever" you can get a bunch of folks to agree to believe(the simplest definition of a church , to me).
ALL charitible actions can still exist without the organization profitting,but the more organized, the less likely it is that that will occur.