Desmond died before Jason was born.[or so everyone beleives. His spirit is actually traped in a dream plane]
He was killed [seperated from his physical body] in the dream plane by Alexandreil Teppin possessed by Thearon. In penance for this, Alexandreil agrees to replace Desmond as the Center of Paragangia until Jason is old enough to take over.
Jonathan also held himself accountable because the dream powers used to kill Desmond were something Jonathan had taught Alexandreil.[and/or because he was the reason Alexandereil was in the right place at the right time to allow Thearon to do this] Jonathan goes into exile, confessing his involvement in Desmonds appaarent death to protect Alexandreil from exile. Jonathan knows he can survive exile and knows Alexandreil cannot.
Desmond Harris Grew up in the HomeWorld LDS colony with Rae. his parents died when he was very young[I still need to explain exactly what happened to them]. He Left behind His LDS beliefs when he became Paragangian, but returned to those beliefs near the end of his [first] life when he met Gloria Scott [and her father Jamie Scott ] and conceived Jason. Because He remembered that the Gospel is all about families.
He was instramental in the rebuilding of the Paragangian empire and the building of the HomeStation to replace the imploded planet Paragangia.
After Harris and Jason become Center of Paragangia, they discover that Desmond Harris is not really dead but trapped in the minimal dream plane of the station, and he can only appear in the dream plan when all the people who were there when he was trapped there are sleeping on the station at the same time.[ALexandreil, Jonathan and maybe Sen'tran?] only when Jonathan comes to the station is he able to re-emerge. but I think when Alexandreil becomes dreambound with Chathalen, Desmond is awakened and they share the minimal dreamplane in a concious state.
Alexandreil Teppin is trapped in the same way when Thearon again takes control of him and sends him to kill Harris and Jason, but Chathalen intervenes and both Alex and Chathalen are dreambound. Jonathan decides to trade places with Desmond, So that he can be with Alexandreil [Jonathan and Alexandreil were very close, and had been separated for 20 years due to Jonathan's having been exiled for his confessed involvement in the death of Desmond ]
Jonathan convinces Desmond to take over Jonathan's body temporarily so that he can talk to his wife Gloria, who is unable to enter the dream plane. Then Jonathan refuses to trade back. Inhabited by Desmond's spirit the body which was Jonathan transforms into the body of Desmond. Thus, Desmond is resurrected, and Jonathan choses to remain dreambound with Alexandreil
In the begining of Destiny of Dreams, his significance is that both Jason and Harris are named after him, and are both in some way his Heir as Pargan. Harris has spent his life looking for the true Heir because although he was also born to replace Desmond, he feels the biological decendant should be Paragn. THey all know a biological decendant exists because Paragan [Desmond, acting as PAragan] left him a message embeded in the wall gloria painted. The message can only be opened by Jason, it is coded to his genetics,
in the end when they open the wall, it also contains a package that can only be opened by Harris Jenzar: a set of LDS Scriptures, which Harris takes to heart instantly in a way which horrifies retrotechnologist Jason.
In the History of Paragangia book, which is the story of Jason's parents, Desmond is still a Negotiator for Earth to Paragan , but is also serving as Center of HomeStation, and secretly also Paragan [Center of the empire]His excommunication from the LDS church was because he was angry that Paragangian people were not allowed to be baptized, and spoke out publically against the prophet on this point. As a result he was called to a disciplinary hearing which he publically refused to attend. Thus he was excomunicated. As a result, the Empire never gave the church permission for Paragangians to be baptized, so the church would not baptize them.