The idea of Christ being begotten in an act of conception is carried forward with the analogy of the labor of childbirth. As such, the Son was brought forth as if a baby was being born.
Why was the lamb slain at the foundation of the world? So that light could become darkness, good could become evil, the sinless could become sin, and we could have sentient life with free will.
Broadly speaking there are three contexts in which “foundation(s) of the Earth/world” are the scriptural basis for how we can understand three important concepts in our unified theory of everything.
We need to demonstrate a logical progression [from] the elements produced by nucleosynthesis [to] organic life with replicating DNA. Fortunately science did a bang up job of documenting it.
Jesus Christ, the Word of God, is also called the lamb that was slain [from] the foundation of the world, which we take to mean the lamb that was slain [at] the foundation of the world.
We've resolved what popular science (SciPop) calls "the Big Bang" with nucleosynthesis as described in Genesis 1:3. However, it would seem that before the Big Bang there was a Loud Howl.
The foundation of the world was an act of conception. Wisdom (Hydrogen, H+) fused with the Holy Spirit (alpha Oxygen, αO2-) to form the Hydroxyl ion (OH-). This existed with Wisdom (H+) to be the deep (H2O).
If God knew the consequences of making creation before he created it but he chose to create it anyway, it means that the sacrificial death of Jesus Christ on the cross at Calvary was Plan A.
There was an act of conception and the Son was begotten. This is referred to in the Greek phrase the foundation of the world. So, why was the lamb slain from the foundation of the world, his own birth?