User blog comment:B214/Volume 21 info & spoilers/@comment-93.105.246.116-20160606130720/@comment-1359322-20160606145044

The Bible God already started to create the Sacred Gears even before the Great War, why do you think Azazel thought of his first Artificial SG Blazer Shining Aura Darkness Blade while he was still an Angel.

Also remember in DxD-verse, Gods do age Odin aged, Zeus aged and so on. And they grow weaker as they aged. Even if the God took some rest, it may not let him recover enough as he is.