Sometimes we need to part ways with those who are not part of God's plan for our lives. The Lord has a good plan for us, but if we have people in our lives that are just not part of what the Lord is doing through us, we need to pull away. This doesn't mean certain people around us are from the devil. It just means God is very precise in all that He does.
The Lord said to Abram after Lot had parted from him, "Look around from where you are, to the north and south, to the east and west. All the land that you see I will give to you and your offspring forever. - Genesis 13:14-15