The Genesis of the DC Multiverse (Crisis on Infinite Earths #1, Multiversity Guidebook #1, Justice League Incarnate #4 and New History of the DC Universe #1)

I've made a few posts before covering and breaking down the creation of the DC Multiverse as seen in Justice League Incarnate and Dark Crisis in-depth, (links here and here). To recap those quickly, Joshua Williamson IMO actually did an excellent job taking from all the major accounts from DC history, reconciling Mark Wolfman and George Perez's Crisis on Infinite Earths, Grant Morrison's Multiversity and Scott Snyder's Dark Nights Metal sagas.

Now, Mark Waid's A New History of the DC Universe #1 did so too with even more breadth and depth, with the series of course actually focusing on the history and timeline of the DC Multiverse, with the intention of being the definitive documentation of current continuity. So I want to do another to break things down and clear things up for future reference:

To break things down quickly and clear things up:

• "In the beginning, everything was nothing, an infinite black void of darkness." (COIE)
• This infinite darkness is indeed the Great Darkness or Great Evil Beast, the primordial evil that is the opposite of the Presence or God and represents nothingness. Based on theological philosophy, "to be" is good, so evil is actually a corruption of creation from an external "nothingness" that was there before the all-good God created everything. (See Alan Moore's Swamp Thing)
• "There was also the Source, the infinite force of creation" (A New History), which clarifies the Source as the one true Creator of the Omniverse
• Note: The Source has always been based on the Biblical God. From the beginning in Jack Kirby’s Fourth World saga, and has been continuously implied and now confirmed.
• Its portrayal as a flaming hand burning messages on a wall is based on classical imagery of God doing the same in the Old Testament, such as when He wrote the 10 commandments in Exodus or in the Book of Daniel to warn King Belshazarr. Highfather’s name is Izaya (Isaiah), his first meeting with the Source was basically like Moses’ burning bush moment and him wielding a shepherd’s staff intentionally portrays him as its prophet.
• John Ostrander alluded to the Source and Presence’s (the usual representation of the Judeo-Christian God in DC) connection in his Spectre run
• Geoff Johns’ Day of Judgment has Scott Free say the Source was in Heaven 
• Scott Snyder in Death Metal that wrote Wally explicitly (probably for the first time) saying the Source and Presence are the same being. 
• The light of life (likely the same as White Light of the Life Entity) shines in the darkness and grows to become the pure "perfection" of the Overvoid. (Multiversity and JLI)

• The "Flaw" or Multiverse is brought forth from there, turning the Overvoid into the canvas of fiction, the blank comic page where stories are drawn. Worlds and stories are made. 

• Perpetua and other cosmic agents, referred to as "Hands" or "Super-Celestials", are "sub-creators" in the sense that they created smaller local Multiverses shaping energy from the Source. This of course means that they did not create "Ex Nihilo" or from nothing. (A New History)
• The original Monitor, Anti-Monitor and World Forger were directly created by Perpetua as part of her plan to corrupt her Multiverse. The Source catches wind of this, sends an agent to banish her and the Multiverse is reset and remade (A New History).
• Shown originally with more details in Scott Snyder and Jorge Jiminez's Sixth Dimension arc from Justice League.
• The Pre-Crisis Multiverse is an unstable false Multiverse created from Krona's experiment (COIE)
• That aside, like many worlds, the natural uncorrupted Multiverse, stable or not, has God, Angels, Demons and gods.

Summing it all up:

The Source is the true primordial uncreated creator and first cause of all things. It is the same being or related to the Presence (one being an aspect of the other, or being co-equal in a similar model to the Trinity). Both are stand-in representations of The God with a capital G. His light created the Overvoid, the canvas of creation.

The Great Darkness predates all creation and is the opposite of The Presence, a being of light and goodness that created everything, as it is a being of darkness and nothingness which lead to the corruption of things to create evil.

The Hands are the writers and artists, with the Source giving them creativity, energy and ink. The Overvoid is the comic page. They don't create from nothing but take what was given to them and shape it, like we do in real life to "create" things. If the Source is Eru Iluvatar, the Hands are the Valar.

The Monitors descend from Perpetua and come from an older version of the DC Multiverse that was scrapped with her being fired and the first Monitors being reassigned. The Angels, Demons and gods are natural parts of the Multiverse that either directly or indirectly descend from God (the Presence or Source).