The wiki gives a clear point system on how a Divine is chosen. Sorry if posted.
http://dragonage.wik...Divine_election
Support war table operation
Supported candidate earns +10 points
Major choices
In Hushed Whispers
"You're our allies." ("We would be honored to have you fight as allies at the Inquisition's side.") – Offer the rebel mages a full alliance.
Leliana +10, Cassandra -5, Vivienne -10
"You're our prisoners." ("You will surrender yourselves as prisoners and conscripts of the Inquisition.") – Conscript the rebel mages into the service of the Inquisition.
Leliana -10, Cassandra +1, Vivienne +10
Champions of the Just
"Rebuild as our partners." ("Your Order is a symbol that holds the people's respect. That cannot die today.") – Ask the templars to join you as free allies.
Leliana +1, Cassandra +10, Vivienne +5
"Then yield and serve us." ("There is no time. If the old Order is too broken to stand, then become knights under the Inquisition!") – Convince the templars to disband and become part of the Inquisition instead.
Leliana +1, Cassandra +5, Vivienne -5
Wicked Eyes and Wicked Hearts
Celene dead:
Gaspard and Briala:
Leliana +5, Cassandra -5, Vivienne -10
Gaspard alone:
Cassandra +10, Vivienne -1
Celene alive:
Public truce between all three:
Cassandra +1, Vivienne -5
Gaspard executed:
Vivienne +1
Gaspard spared:
Leliana +1, Vivienne +5
Here Lies the Abyss
"Help the Inquisition." ("You stay and do whatever you can to help.") – The Grey Wardens help the Inquisition. They may be vulnerable to corruption.
Leliana +5, Cassandra -5, Vivienne -1
"Get out of Orlais." ("You leave.") – The Wardens are banished from Orlais. They do not help the Inquisition.
Leliana +5, Cassandra +5, Vivienne +1
Conversations
Inquisitor speech
"I'll do it because it's right." ("This isn't about a greater message. We have an enemy and we have to stand together.")
Leliana +5
"I will lead them to vengeance." ("Vengeance is what I want. For the lives taken, and the lies spoken.")
Leliana +1, Vivienne -5
"I'll be a servant of faith." ("I will restore what Corypheus could never destroy. I am but a servant of the Light.")
Cassandra +5, Vivienne +1
"A dwarf/elf/Qunari will stand for us all." ("The Inquisition is for all.")
Leliana +1, Cassandra -1, Vivienne -1
"I fight for order, not faith." ("Our concern must be the order and safety of this world. Not the next.")
Cassandra +1, Vivienne -1
"I'll set an example as a mage." ("With fear running rampant, they need to see a mage standing for what is right.")
Leliana +1, Vivienne +5
"I'll do it for my own power." ("The Inquisition will be a force to rival any in Thedas. In my name.")
Leliana +5, Cassandra -1
Cassandra
Cassandra and Giselle cutscene after Wicked Eyes and Wicked Hearts
"You'd be perfect." ("I think you'd make an excellent choice.")
Cassandra +5
"Maybe the Chantry should end." ("Perhaps the Chantry needs more than just change.")
Leliana +1, Cassandra -1
Do you want to be Divine?
"You'd make a good Divine." ("I think you'd make an excellent choice.")
Cassandra +5
"Forget the Chantry." ("I don't see why you think the Chantry is so worthy of reform.")
Cassandra -5
"Perhaps there's another way." ("There are other ways you can change things.")
Cassandra -1
Leliana
After Wicked Eyes and Wicked Hearts
"The Chantry preached hate." ("It was the Chantry that taught people hate and fear.")
Leliana +1
After What Pride Had Wrought
"Why does change matter?" ("I don't see why you'd bother.")
Leliana +1
"It's a noble goal." ("It is certainly something worth working for.")
Leliana +1
"I'd support you." ("I think you would make a good Divine.") – Support Leliana as the new Divine.
Leliana +1
"The world needs that Chantry." ("The world could certainly use the force for good you describe.")
Leliana +1
Vivienne
Warm approval
"Andraste and the Maker cast very large shadows."
Vivienne +5
After In Hushed Whispers
"We need the Circle back." ("The Circle has to be restored if we want to keep the peace.")
Vivienne +1
"We need mages in the Chantry." ("Mages shouldn't be kept out of the Chantry. Who knows the dangers of magic better than a mage?")
Vivienne +5
Investigate
"So teach them not to fear." ("It will take time, but people can learn not to fear magic.")
Vivienne +1
"They deserve what happens." ("They destroy themselves then, and they deserve it.")
Vivienne -1
After Wicked Eyes and Wicked Hearts
"You'd make a good Divine." ("Actually, I think you fit the criteria perfectly, Vivienne.")
Vivienne +1
"I agree." ("I think Cassandra would be best for the job.")
Cassandra +1
"What about Leliana?" ("Leliana might be a better choice than Cassandra, don't you think?")
Leliana +1
"I'll make sure they do." ("A few words to the right people, and we can ensure no one objects to you taking the Sunburst Throne.")
Vivienne +5
Josephine
(About grand clerics consolidating the Chantry's power instead of comforting the masses) "It's needed more than ever." ("The Chantry should be a place of hope, not another group scrambling for answers.")
Leliana +1, Vivienne +1
Mother Giselle
"The Chantry did terribly." ("It would be difficult for us to do worse.")
Leliana +1
"I hope so." ("The Temple of Mythal held knowledge safe for untold centuries. It would be tragic to lose it.")
Leliana +1
Dorian
(About the Chantry being a relic) "I agree with you." ("I share your opinion, actually.")
Leliana +1, Vivienne -1