43 When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest, and findeth none. 44 Then he saith, I will return into my house from whence I came out; and when he is come, he findeth it empty, swept, and garnished. 45 Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
Going back to your old ways after you have been delivered, doesn\’t bring back the same devil only but seven; not two or four or maybe five, but seven wicked devils. The question is, what makes the house (your body) empty. The answer lies in 1 Corinthians 6:19-20
19 What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? 20 For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God\’s.
You are either empty or filled with a spirit being (the Holy Ghost or devils; the greater one or he that is in the world (1 John 4:4 )), and you will know because whoever you have in you and around you, will lead you to do the things he wants you to do; or will keep you from doing the things you do not want to do.
In summary, by your fruits or the fruit you bear you will know who lives in you or is trying to deceive or influence you from the outside.