The spirits that dwell in these tabernacles on this earth, when they leave them go directly into this world of spirits. What! A congregated mass of inhabitants there in spirit, mingling with each other, as they do here? Yes, brethren, they are there together, and if they associate together, and collect together, in clans and in societies as they do here, it is their privilege. No doubt they yet, more or less, see, hear, converse and have to do with each other, both good and bad. If the Elders of Israel in these latter times go and preach to the spirits in prison, they associate with them, precisely as our Elders associate with the wicked in the flesh, when they go to preach to them (DBY, 378.)
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Spirits are just as familiar with spirits as bodies are with bodies, though spirits are composed of matter so refined as not to be tangible to this coarser organization. They walk, converse, and have their meetings; and the spirits of good men like Joseph and the Elders, who have left this Church on earth for a season to operate in another sphere, are rallying all their powers and going from place to place preaching the Gospel, and Joseph is directing them, saying, go ahead, my brethren, and if they hedge up your way, walk up and command them to disperse. You have the Priesthood and can disperse them, but if any of them wish to hear the Gospel, preach to them (DBY, 379).
via LDS.org – Melchizedek Priesthood Chapter Detail – The Spirit World.