Is. 9.6 the father refers to the founder, author and creator, and the kingly Messiah; the man Christ Jesus is a Father to His beloved people: "Like as a father pitieth his children, so the LORD pitieth them that fear him" (Ps. 103.13). "But now, O LORD, thou art our father; we are the clay, and thou our potter; and we all are the work of thy hand" (Is. 64.8).

It occurred to me that if you want to make Jesus the Father in Is. 9.6 then it stands to reason the Father in the NT is the son, but of course, no such verses exist that say that. Would you want a blind faith such as that? Clearly in the NT Jesus is not the Father so the father in Is. 9.6 is not the Father in the NT.