Because God is love, the Godhead was able to exist from eternity.
I tweak the "omni" definitions as follows to make sure they are logically consistent, and add the term "omnibenevolent":
Listen to 2 Corinthians 9:
And though they go into captivity before their enemies, from there I will command the sword that it slay lake party girls, and I will set My eyes against them for evil and not for good.
Parents with young children can see this for themselves.
Bring them down on the heads of all the people; those who are left I will kill with the sword.
No data is shared with Facebook unless you engage with this feature.
This simple premise actually proves that the omnis are logically correct.
If you were always aware that God is with you, and sees you, how much sin would you allow?