Moreover whom He predestined, these He also called; whom He called, these He also justified; and whom He justified, these He also glorified.
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, having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will
having made known to us the mystery of His will, according to His good pleasure which He purposed in Himself, that in the dispensation of the fullness of the times He might gather together in one all things in Christ, both which are in heaven and which are on earth--in Him. In Him also we have obtained an inheritance, being predestined according to the purpose of Him who works all things according to the counsel of His will
The Lord brings the counsel of the nations to nothing; He makes the plans of the peoples of no effect. The counsel of the Lord stands forever, The plans of His heart to all generations. Blessed is the nation whose God is the Lord, The people He has chosen as His own inheritance.
2 Timothy 1:9
[God,] who has saved us and called us with a holy calling, not according to our works, but according to His own purpose and grace which was given to us in Christ Jesus before time began,
Isaiah 6:8-10 (John 12:40 quotes this passage)
Also I heard the voice of the Lord, saying: "Whom shall I send, And who will go for Us?" Then I said, "Here am I! Send me." And He said, "Go, and tell this people: 'Keep on hearing, but do not understand; Keep on seeing, but do not perceive.' "Make the heart of this people dull, And their ears heavy, And shut their eyes; Lest they see with their eyes, And hear with their ears, And understand with their heart, And return and be healed."
But although He had done so many signs before them, they did not believe in Him, that the word of Isaiah the prophet might be fulfilled, which he spoke: "Lord, who has believed our report? And to whom has the arm of the Lord been revealed?" Therefore they could not believe, because Isaiah said again: "He has blinded their eyes and hardened their hearts, Lest they should see with their eyes, Lest they should understand with their hearts and turn, So that I should heal them."
for it is God who works in you both to will and to do for His good pleasure.
Truly, this only I have found: That God made man upright, But they have sought out many schemes."
In case you need proof of it now.
2 Timothy 3:16-17
All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work.