Should i trust this guy?i can't decide...?

lately i've met a guy who tryes to keep in touch with me but somehow i feel he's dangerous in some ways.he did somethings to show me that he will be a faithful member & the things were good enough to make us believe him. but in my heart i feel he is my enemy & he's doing this to let us down & make us weak for fighting with vamps...but i don't have any clue,i just feel this...what should i do?i'm totally confused!