Who is who

"But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His." Romans 8.9

In my view, this is one of the most incisive biblical statements. It does not leave room to doubts or discussion. Those who have been possessed by the Spirit of God are so different from those who have not, just as the difference between wine and milk. The behavior of each one bears witness to who is who.

The Spirit and faith

"And Pharaoh said to his servants, 'Can we find such a one as this, a man in whom is the Spirit of God?'” Genesis 41.38

Only those who are possessed by the Spirit of God make a difference. As a matter of fact, even the the children of darkness recognise them. However, in order to have Him, we must pay the price of sacrifice.

ANOINTING

"Thus Esau despised his birthright."       Genesis 25:34

Adam rejected God's anointing, Esau rejected Isaac's anointing, Judas Iscariot rejected Jesus' anointing and the same spirit of rebelliousness has continued to be passed on from generation to generation. 
Those who turn their backs on the anointing of the Divine are subject to Satan's power. You can't have God as your Lord and the devil as your lord at the same time. You are either a child of God or a child of the devil. You are either a temple of the Holy Spirit or a vessel of the devil.
This is why most believers are troubled, unsuccessful and possessed by demons. They have accepted Jesus as their Savior but have rejected Him as their Lord.