To expand a bit on Simon Holzman's answer, in the United States non-profits don't pay taxes on their non-profit activities. As such, churches don't pay anything on donations. read more
As such, churches don't pay anything on donations. They do pay taxes if they have retail sales (books, CDs, etc.) and on investments (if they own real estate and rent it out as a profit-generating business, they are taxed as a business.) But for money involved in church-ing, they don't and shouldn't pay any taxes at all. read more
If your church is not tax-exempt, you can't deduct your tithes. Pay your tithes and other contributions in a way that leaves a paper trail or gets you a receipt. You can't claim a deduction for loose cash in the collection plate without a receipt. read more