This false teaching (which comes along with the Calvinism and “reformed” Protestantism false teachings) says that God picks (picked) and chooses (chose) who to save before the foundation of the world (and also thereby who will be lost forever), and that man has no choice nor free-will in the matter. I think it’s best to simply give Wayne Jackson’s rebuttal to this false teaching, as I cannot say it any better:
As he commences his letter to the saints in Ephesus, Paul declares that God: “chose us in him [Christ] before the foundation of the world … having foreordained [predestinated – KJV] us unto adoption as sons through Jesus Christ unto himself?” (1:4-5).
Does this passage teach that our salvation is strictly a matter of God’s arbitrary election, settled before the world was made, irrespective of any choice that we might exercise in the matter?
That was the philosophy of John Calvin. The Presbyterian Westminster Confession of Faith stated: “By the decree of God, for the manifestation of His glory, some men and angels are predestinated unto everlasting life, and other foreordained to everlasting death” (Article III).
This concept makes void every passage in the Bible that teaches human responsibility. If one’s eternal destiny was sealed from the beginning of time, what is the purpose of preaching to the lost?
The key phrase in Ephesians 1:4 is “in him.” It was not the case that God chose certain individuals to be either saved or lost; rather, the Lord foreordained that a certain class of persons would be saved.
What sort of class? Those who submit to Heaven’s divine plan of redemption, which, in this dispensation, involves obeying Jesus Christ (Hebrews 5:8-9), and entering into that relationship that is described as being “in him” (cf. Galatians 3:26-27).
To say the same thing in another way, before the world’s foundation, God elected to save those who would be obedient to His Son. Underline “chose us in him,” and record this comment: Not individual election, but class election.
[ref: Jackson, Wayne. “Ephesians 1:4 – Predestination.” ChristianCourier.com. https://www.christiancourier.com/articles/784-ephesians-1-4-predestination]