No, unfortunately you cannot deduct your church contributions on Schedule C. Schedule C is to be used strictly for reporting income and expenses related to your business.
If you are unable to file Schedule A for itemized deductions, then you will not be able to take a deduction for your church contributions. I am giving you a link below to the IRS regulation which outlines this requirement.
I wish I could have given you a better solution, but those are the current regulations.
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