We cannot provide you with specific tax advice, for which you should check with a tax professional.
The purchase of ULC products and supplies can be deducted against income generated from your work as a minister. If you are employed, you will deduct such purchases as employee business expenses, or request reimbursement from your employer. There are limitations to how much you can deduct for employee business expense, check with your tax preparer.
If your work as a minister is self-employment (wedding ministry, for example) you would deduct such expenses on Schedule C (report of profit or loss).
Purchases are not considered charitable contributions. Free will donations made to the church, where you don't receive anything in return, are deductible as contributions, subject to any limitations imposed by the IRS on contributions.
An excellent source of current information, tips, and guidelines for filing taxes as a minister, we highly recommend the Zondervan Tax Guide for Ministers. This excellent book is written by a leading CPA, who is a specialist in this field of taxes. It is updated annually, and is highly useful for those who earn income as ministers. If you do not earn income as a minister, you cannot deduct the cost of supplies and materials, and you don't need this book.
Zondervan Tax Guide for Ministers - 2006