I don't think there is any doubt that a thief is a liar. He has to lie many times to conceal that he sneaks around and steals other people's items. I'm not sure that a liar is always a thief. I think a liar is a thief most times but not all.
I hate to say this about my own personality, but here goes, I believe this. I have seen it repeatedly in my life, and I hate that people are capable of this. I told my husband that once something has been taken, and I don't want this person in my life or house any more. How can a liar and a thief not know that they are hurting someone? They know, and how can they live with themselves? Do they know that Satan is in control of their lives?
No being a thief doesn't make you a liar nor does being a liar make you a thief. In both situations you're not necessarily a good person but still. a thief is more than likely going to be liar as well but maybe not. just because some people are bad doesn't mean that they're entire bad. I believe that everyone has some kind of good in them.