I just thought, John 16:13 - when that one arrives, the spirit of the truth, he will guide you into all the truth, for he will not speak of his own impulse, but what things he hears he will declare to you the things coming.
Jesus says the spirit of truth will instruct you and NOT of his own impulse. The WT when baptizing replace spirit with spirit directed 'organization', so that's also why they claim to be the faithful slave and bypass that.
THe true faithful 'slave' is this spirit of truth, giving the proper food at the proper time.