Isiaiah did not such thing. Look up councilor in the BLB you find the word is a participle. He either consults or councils the everlasting father. The permanent father is the God of the final messiah.
Yet Jesus Himself said the He and His Father are one. Even His enemies knew that He claimed equality with God. How could He be equal to God, without being God? Besides, John opens his gospel with these words:
“1 ¶ In the beginning was the Word, and the Word was with God,
and the Word was God. 2 He was in the beginning with God. 3 All things were made through Him, and without Him nothing was made that was made.” (Joh 1:1-3 NKJV)
“
And the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth.” (Joh 1:14 NKJV)
As for Child in Isaiah 9:6 counselling the Father, that doesn't seem to fit, because between "Counsellor" and "Everlasting Father" comes "Mighty God":
For unto us a Child is born, Unto us a Son is given; And the government will be upon His shoulder. And His name will be called Wonderful, Counselor, Mighty God, Everlasting Father, Prince of Peace.