Here is the Biblical proof you wanted
Romans 8:29-30 Because those whom He foreknew,
He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brothers; 30 and those whom He predestined, He also called; and those whom He called, He also justified; and those whom He justified, He also glorified.
Ephesians 1:4-5 just as
He chose us in Him before the foundation of the world, that we would be holy and blameless before Him in love, 5 by predestining us to adoption as sons through Jesus Christ to Himself, according to the good pleasure of His will,