You are right, non-existent people like Jesus can never lie. (or do or say anything else) They also can't help you when you're hungry or when you need a REAL friend or helpful leader in the HERE and NOW. (ya know, reality) Honesty comes from within humanity, just like any and all other virtues or vices.

Asking how someone can follow the path of honesty without a leader is like asking how can a person be honest if they are not being watched all day. Are you only good if you are being watched? Are you really actually honest on your own then?