“If it is not the church which can determine and authenticate the canon of Scripture who can?”
There was a day, where it was the roman church who “authenticated” the canon. They largely got it right. After the Reformation, this has been revisited with far more detail and authenticated by protestants, correcting earlier errors.
“If it is not the church which can determine and authenticate the canon of Scripture who can?”
If you surrender your authority externally to another then it is not yours to surrender to God when you go within. Go within, find the Holy Spirit and allow it to guide you.