This should be a matter of concern to knowledgeable readers, since Rutherford confesses he was not led by the Holy Spirit in his writing. Rather, the Watchtower's second president taught that the Holy Spirit ceased to function in 1918 and was replaced by invisible spirit persons.

Seldom mentioned today, this teaching found expression in various publications but is perhaps most clearly stated in Rutherford's book Preservation (pages 193-194): "By his spirit, the holy spirit, Jehovah God guides or leads his people up to a certain point of time, and thus he did until the time when 'the comforter' was taken away" in 1918. Similarly, during Rutherford's presidency and around the time he wrote his interpretations of Daniel's prophecies, The Watchtower of October 1, 1932 presented the same thought on page 294:
The Lord Jesus came to his temple in 1918, and that would mark the time of the cessation of the work of the holy spirit as an advocate, helper and comforter of the members of the church on earth. There the holy spirit was taken away.
In his book Preservation Rutherford wrote this on page 51:
After the holy spirit as an advocate or paraclete ceased to function in behalf of the consecrated, then the angels are employed