“He indeed was foreordained before the foundation of the world, but was manifest in these last times for you.”
before the foundation of the world
“Foundation” comes from two words: firstly, “cast” and secondly, “down.” It means “laying down, a casting down.” God threw the universe into space by simply speaking a word. God laid down creation as a foundation. It was God who founded the world, not some neutral process.
“Father, I desire that they also whom You gave Me may be with Me where I am, that they may behold My glory which You have given Me; for You loved Me before the foundation of the world,” (John 17:24).
John 17 refers to the pre-temporal love of the Father for the son.
God chose believers in Christ before the foundations of the world,
“Just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love.” (Ephesians 1:4).
The Bible also uses the phrase “the foundation of the world” in the sense of from creation onwards:
“That it might be fulfilled which was spoken by the prophet, saying: “I will open My mouth in parables; I will utter things kept secret from the foundation of the world,” (Matthew 13:35).
“Then the King will say to those on His right hand, ‘Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world,’” (Matthew 25:34).
“that the blood of all the prophets which was shed from the foundation of the world may be required of this generation,” (Luke 11:50).
“For we who have believed do enter that rest, as He has said:“ So I swore in My wrath, ‘They shall not enter My rest,’ although the works were finished from the foundation of the world,” (Hebrews 4:3).
“He then would have had to suffer often since the foundation of the world; but now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself,” (Hebrews 9:26).
“All who dwell on the earth will worship him, whose names have not been written in the Book of Life of the Lamb slain from the foundation of the world,” (Revelation 13:8).
“The beast that you saw was, and is not, and will ascend out of the bottomless pit and go to perdition. And those who dwell on the earth will marvel, whose names are not written in the Book of Life from the foundation of the world, when they see the beast that was, and is not, and yet is,” (Revelation 17:8).
God transcends His creation; He is bigger than time and space.
Our pint-sized brains can neither comprehend God nor His work. If we knew everything, we would be as smart as God.
We dare not reject something in the Bible simply because we do not understand it. That is also true in natural human life. We do not understand electricity, but we know it exists. We accept that space vehicles can go to Mars, but we may not know the technical reasons for it. We get it without attempting to understand it. It is the same in the realm of the spiritual. We accept it because God says it, and that settles it.