Bit late to this (as usual). T.b.h. Nailit, I find the 'Born Again,, evangelistic types really hard to deal with and tolerate, so I do understand how you feel. Yes I have had to deal with it and it makes me feel uncomfortable (and I'm a practising Christian!).
I think in your case I might say something like 'Look, mate, I am working with God in my own way. I can ask others about any queries and problems. We will get on better if you don't preach at me. Then I'd feel free to ask you if I wanted any advice.' I would hope that that might work. The passionate, evangelical types don't understand the hackles that they cause to rise and they do us all a disservice. Sorry you're stuck with one - don't write the rest of us off, please, and please keep on with delivering food to people who need it. :)