We do stress that point, that the barrier to donate should be as low as possible. Still, some churches go as far to say donations can't/shouldn't be made on credit do to their individual beliefs, and would only take ACH transfers as they pull directly from a bank account.
Merchants are now seeing a lot of payments by debit card which are not loans (direclty out of bank account). And there are still a lot of Amex cards out there that require full payment each month which is not really a loan.