I agree with the two previous responses that gifts are not considered taxable income be the recipient. In this case however, I believe that the IRS would consider this "gift" as actually a payment for past or future services you performed or will perform for the church. Therefore, I believe this "gift" would be taxable to you as self-employment income. You would be allowed to deduct expenses you incurred while performing your work for the church against this income.
In my opinion, the person giving the money to the church would not be able to deduct the $5000 amount as a charitable deduction as he specified where the money was to be spent.
