Those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified. (Romans 8:30)
Between eternity past in God’s predestination, and eternity future in God’s glorification, none is lost.
No one who is predestined for sonship fails to be called. And no one who is called fails to be justified. And no one who is justified fails to be glorified. This is an unbreakable steel chain of divine covenant faithfulness.
And so Paul says,
And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ. (Philippians 1:6)
[He] will sustain you to the end, guiltless in the day of our Lord Jesus Christ. God is faithful, by whom you were called into the fellowship of his Son, Jesus Christ our Lord. (1 Corinthians 1:8–9)
These are the promises of our God who cannot lie. Those who are born again are as secure as God is faithful.