“He that walketh with wise men shall be wise: but a companion of fools shall be destroyed.”

What i think this means is that if you hang around smart and wise people, you will be like them, smart and wise. If you hang around people that get into trouble a lot, then you will become like them. We become like those we choose as our friends. If you want to become a bad person then hang out with the bad crowd. If you want to become a good person you must go with the good crowd.