You can take a withdrawal and then give it to the charity but you will have to report the IRA distribution on your tax return as taxable income. You could then claim the contribution as an itemized deduction on Schedule A (assuming you can benefit from itemizing). The deductible amount will be limited to 50% of your adjusted gross income for the year but you can carry over (for up to 5 years) any unused amounts and deduct them (still subject to the 50% limitation) in those future years. Last year if you were over age 70 1/2 you could have IRA distributions sent directly to charities and not claim the distributions as taxable income (up to $100,000) but that exception expired 12/31/09. However, there is proposed legislation to extend the exception to this year but it has not been signed into law yet.
Another alternative is to list the church as the beneficiary of your IRA and upon your death the funds will be distributed from your IRA to the church tax-free.
If the church is designated as beneficiary of my IRA is that amount also limited to $ 100,000