It brings up a good point, and when it boils down to it, I think there is only a difference of degrees. True, he doesn't worship the scarf, but if he actually is attributing some supernatural quality (luckiness) to it, then I think they are beliefs of the same nature. For example, would a person very relaxed in their religious beliefs be on the same level as someone who truly deeply believed that he had a lucky scarf?
Of course, you also have to ask if this person actually does believe that the scarf is lucky. For example, anytime I run a yellow light I kiss the my hand and touch the roof of my car for "good luck," or to stave away misfortune. Do I actually believe it helps? No, of course not. It doesn't do a thing. Does the lucky-scarf wearer feel the same about his scarf? This helps to clarify the difference between a lucky scarf and believing that a loving God is watching you, but how far can you take that difference? In this case, it seems that the only feature separating the two is strength of belief. So I actually would have to side with your christian friend, assuming that the scarf-ed one actually believes it brings him luck.
I come back to, though, the difference between believing and truly believing. Do these atheists your friend talks about actually believe that their underwear is lucky? I doubt it.
Of course, you also have to ask if this person actually does believe that the scarf is lucky. For example, anytime I run a yellow light I kiss the my hand and touch the roof of my car for "good luck," or to stave away misfortune. Do I actually believe it helps? No, of course not. It doesn't do a thing. Does the lucky-scarf wearer feel the same about his scarf? This helps to clarify the difference between a lucky scarf and believing that a loving God is watching you, but how far can you take that difference? In this case, it seems that the only feature separating the two is strength of belief. So I actually would have to side with your christian friend, assuming that the scarf-ed one actually believes it brings him luck.
I come back to, though, the difference between believing and truly believing. Do these atheists your friend talks about actually believe that their underwear is lucky? I doubt it.