In Isaiah 1:18 God invites us to reason with Him. In order to reason we must use our minds and intellect.
John 15:26-27
26 But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:
27 And ye also shall bear witness, because ye have been with me from the beginning.
KJV
John 16:13
13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
KJV
Acts 2:18-21
18 And on my servants and on my handmaidens I will pour out in those days of my Spirit; and they shall prophesy:
19 And I will shew wonders in heaven above, and signs in the earth beneath; blood, and fire, and vapour of smoke:
20 The sun shall be turned into darkness, and the moon into blood, before that great and notable day of the Lord come:
21 And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved.
KJV
1 Corinthians 2:11
11 For who among men knows the thoughts of a man except the spirit of the man, which is in him? Even so the thoughts of God no one knows except the Spirit of God. NAS
God is spirit and God promised to pour out His Spirit on mankind. Now unless you believe a spirit has a spirit how can you believe that the sprit that proceeds from the Father is not the Father Himself?