As said by those proclaiming the spirit in their head as their authority.
Backed up by scripture.
Galatians 3:27 For as many of you as have been baptized into Christ have put on Christ.
2 Corinthians 1:22 Who hath also sealed us, and given the earnest of the Spirit in our hearts.
Romans 8:10: Paul tells us, "If Christ is in you, the body is dead because of sin."
Galatians 2:20: Paul speaks of himself and all true Christians: "I have been crucified with Christ; it is no longer I who live, but Christ lives in me."
Romans 8:9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
Galatians 3:27 For as many of you as have been baptized into Christ have put on Christ.
2 Corinthians 1:22 Who hath also sealed us, and given the earnest of the Spirit in our hearts.
"The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned." 1 Cor 2:14
And I will ask the Father, and He will give you another Counselor to be with you forever--the Spirit of Truth. The world cannot accept Him, because it neither sees Him nor knows Him. But you know Him, for He lives with you and will be in you. John 14:16,17
Acts 15:8 And God, who knows the heart, bore witness by granting them the holy Spirit just as he did us. 9 He made no distinction between us and them, for by faith he purified their hearts.
Rely on the Catholic Church if you want but I will rely on the indwelling Spirit of God promised to all of those who truly believe on Him. It's dangerous to blaspheme the Holy Spirit by calling it the "spirit in their head" in a condescending manner.