When we examine the verses which speak of "predestination" we will see that they are speaking of
believers being predestined to putting on new, glorious bodies just like the Lord Jesus' glorious body.
"And we know that all things work together for good for those who love God, who are called according to his purpose, because those whom he foreknew he also predestined to be conformed to the image of his Son, that his Son would be the firstborn among many brothers and sisters" (Ro.8:28-29; NET).
At Romans 8:29 Paul tells us why he says that "all things work together for good" for the saved, those he describes as the called:
"because those whom he foreknew he also predestined to be conformed to the image of his Son."
The reason why "all things work together for good" in regard to the saved is because the saved are predestined to be conformed to the image of the Son. That will happen when the Lord descends from heaven and the saved will put on bodies just like his glorious body:
"But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body" (Phil.3:20-21).
Having Predestined us to Adoption as Sons
The following verse is also speaking of the same destiny of those who are already saved:
"Having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will" (Eph.1:5).
That is the same "adoption" that is in regard to the redemption of the body:
"And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body" (Ro.8:23).
Again, this is speaking of the glorious bodies we will receive when we meet the Lord Jesus in the air.
Being Predestined to an Inheritance
The following verse is also referring to the same exact thing:
"In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will" (Eph.1:11).
Just two verses later we learn more about this inheritance" to which the saved of this present dispensation have been ordained:
"In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, Which is the earnest of our inheritance until the redemption of the purchased possession" (Eph.1:13-14).
The redemption of the purchased possession will happen on the day of redemption and the purchased possession is our new, glorious body:
"And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption...the redemption of our body" (Eph.4:30; Ro.8:23).
So we can understand that the verses which use the word "predestinate" in regard to a person's destiny are not speaking of anyone being predestinated to salvation.