If I say I believe in God, is my political speech organization now tax exempt?Not currently, and most certainly not ever. The last thing the gov't wants to do is provide a law that could effectively make all political donations tax exempt.
Here's an interesting article on the issue:
Backlash Against Tax Exemption Laws
By Austin Cline, About.com
It is an established fact of law and jurisprudence that charitable organizations, including churches, which have tax-exempt status are not allowed to participate in political campaigns on behalf of political candidates. Every attempt to challenge this situation in the courts has failed and resulted in a resounding defeat for those who want to have greater mixing of religion and politics. That is not, however, the end of the story.
A focus of recebt efforts is to make a direct change in how the laws read in order to ensure that churches can become fully active in political campaigns — endorsing some politicians, attacking others, and engaging in politics rather than theology from church pulpits. A pet project of Walter Jones that would effect these changes is titled “Houses of Worship Political Speech Protection Act,” and one version reads thus:
An organization described in section 508(c)(1)(A) (relating to churches) shall not fail to be treated as organized and operated exclusively for a religious purpose, or to have participated in, or intervened in any political campaign on behalf of (or in opposition to) any candidate for public office, for purposes of subsection (c)(3), or section 170(c)(2) (relating to charitable contributions), because of the content, preparation, or presentation of any homily, sermon, teaching, dialectic, or other presentation made during religious services or gatherings.There was a great deal of opposition to this bill and to any similar changes in the tax laws — even from many members of the clergy who might be assumed to benefit the most from such changes. Why would this be a bad law?
more:
http://atheism.about.com/od/churchestaxexemptions/a/politicalchurch.htm