All Scripture Is Inspired and Beneficial for Teaching: page 9:
Someone may ask, What has been the means of communication? This may well be illustrated by a modern-day example. Communications lines have (1) the utterer, or originator, of the message; (2) the transmitter; (3) the medium through which the message passes; (4) the receiver; and (5) the hearer. In telephone communications we have (1) the telephone user originating the communication; (2) the telephone transmitter, which converts the message into electrical impulses; (3) the telephone lines carrying the electrical impulses to the destination; (4) the receiver reconverting the message from impulses to sounds; and (5) the hearer. Likewise in heaven (1) Jehovah God originates his utterances; (2) then his official Word, or Spokesman—now known as Jesus Christ—often transmits the message; (3) God’s holy spirit, the active force that is used as the medium of communication, carries it earthward; (4) God’s prophet on earth receives the message; and (5) he then publishes it for the benefit of God’s people. Just as on occasion today a courier may be sent to deliver an important message, so Jehovah at times chose to use spirit messengers, or angels, to carry some communications from the heavens to his servants on the earth.
steve