If you ignore it your “giving friend” will think you didn’t notice or didn’t need the money after all. Letting it go is not an option!
Try language like this:
“Bob, I want to thank you for your promise to support our work with $50 per month. But I notice that your first gift has not come in to our ministry headquarters yet…or am I missing something?
How can I serve you? Shall I come pick your first check up…maybe we could have a little breakfast together and I’ll take it to the office right away. What is best for you?
The reason I am so persistent on this is that I am not allowed to launch my ministry until I am fully subscribed. This is a serious matter.”
If the donor seems to want to backtrack on his commitment:
“How do you feel about this, Bob? Is God in it? I don’t want to pressure you because of 2 Cor 9:7 (quote it). But it seemed like you were quite sure you wanted to support us….”