FWC not only wants to fight, they believe the battle with the darkness is inevitable. FWC want to gain knowledge of the enemy's tactics and hardware to create better and more futuristic weaponry to better stand up against the Darkness AND WIN.
To me, this sounds like the most logical and best chance to keep the Human species alive.
Dead Orbit: Where are they going to run to? Do we even have ships capable of making it to the next solar system? By looking at what’s on the launch pads in the Cosmodrome, No, we don’t!
New Monarchy: Pffft. Yea, changing the government will fix all these issues. You might as well sit on the proverbial Throne. I will not speculate further.
Osiris: not much as been said about this Faction, but Osiris is a god of the afterlife, ruler of the dead. He was also described as the 'Lord of Love' and the 'Lord of Silence'. Osiris might be a hope for new life after death. Osiris faction could go off in any direction, but little is known about this faction and we will have to wait and see how they apply their namesake to the situation at hand. I may defect to the Osiris Faction from FWC if I like what I see.
Seven Seraphs: next to nothing is known about this faction. However, there must be 7 Seraphs! When you look up a Seraph, it is a type of celestial or heavenly being (AKA Traveler worship?). In Judaism and Christianity, it literally means: “The Burning Ones”. In the Book of Isaiah they are described as Firey, Six-winged beings that fly around the “Throne of God”, and Tradition places Seraphs in the Fifth rank of ten hierarchy (Jewish) and the Highest Ranking angelic beings in Christianity. So one might deduce that the Seven Seraphs may actually be holding out hope for other races from the universe may ‘swoop down and help defend the human race’ –maybe. Or maybe there isn’t just one Traveler. There might be more. Coming…
For now, Future War Cult is the best choice for me, but I am holding out to learn more about Osiris and Seven Seraphs for more details about these two factions. As the Destiny lore begins to unfold, I may change my current view and align myself with one of these two factions instead.