According to the principle of creation, man's spirit was created to grow only through give and take action between the life element from God and the vitality element from man's physical body. Therefore, the spirit man can neither grow nor be resurrected apart from our physical body. So in order that spirit men, who passed away to the other world without having perfected themselves in their physical life on earth, might be resurrected, they must come again to earth and fulfill the responsibility they left unaccomplished in their physical life on earth, through the physical bodies of earthly men, by cooperating with the earthly saints and helping them fulfill the same mission. This is why Jude 1:14 says that in Last Days the Lord will come "with his holy myriads".
In what manner do spirit men cooperate with earthly men to accomplish the will? When earthly saints form a reciprocal base with spirit men, through prayer and other spiritual activities, the spirit men descend and form reciprocal bases with the spirits of the earthly men, on which bases they cooperate. Thus, the spirit men pour out spiritual fire on earthly men, give them the power to heal diseases, and help them do many mighty works. More than that, they enable earthly men to see many facts in the spirit world in a state of trance, give them the gift of prophecy, and inspire them spiritually. Through such activities, substituting for the Holy Spirit, they cooperate with earthly men to fulfill the will of God.