Ephesians 1.

"[7] In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, [8 ]which he lavished upon us, in all wisdom and insight [9 ]making known to us the mystery of his will, according to his purpose, which he set forth in Christ [10] as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth.
[11] In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will..."
This is a passage which along with references to 'the elect' is commonly used to support a calvinist viewpoint. I feel that we encounter considerable problems of interpretation here if we do not factor in God's foreknowledge of how humans will respond to His Son. Surely, the predestination can only arise from this fact as any other view is suggesting that God's 'chosen or 'elect' have been arbitrary choices by God. The principle of freewill is undermined and if many are arbitrarily already condemned when born - then what is the point? This was put into extreme forms in the 18th century by the Jansenists as described in "L'histoire du Chevalier des Grieux et de Manon Lescaut" by L'Abbe Prevost. [Later an opera]
In Acts 15:18 -- “Known unto God are all his works from the beginning of the world.”
There is nothing here to gainsay the importance of foreknowledge as the key.