What do you do when you are handed a religious tract?

So I was eating lunch at Whole Foods and happily proof reading a paper on my ipad.  A man came over to me and said that since I was reading that (the ipad), he wanted to give me this (a seasonal/holly-berry thing that looked to be religion in disguise).  I really didn’t want to discuss anything just then, so I just said thank you, sort of smiled, and went back to work.

I’m not happy about that reaction, though I’m not sure quite why.  I think I left him somewhat deceived, since he might well have thought I was grateful.  Reflecting on this, I realized I don’t have a response I like for these not infrequent occasions.  I definitely don’t want to get in a discussion.

I’m now thinking that perhaps I should say something like, “Thank you, but no thank you.   I think you should keep it and give it to someone who would be much more interested in it than I am.”  And just refusing to explain.

Of course, we do have readers who are religious and who may find these encounters unproblematic.  But also any of us might find them presumptuous and intrusive, whether we’re religious or not.  I’m sure there are many other readings.  BUT WHAT DO YOU DO??