The Mystery of His Will

Known unto God are all His works from the beginning of the world (cf. Acts 15:18). The future is what God has already planned according to His own counsel and purpose.
Long before God made the world, he chose certain groups and individuals for Himself - to have a special relationship to Him. For example, Abraham, the nation of Israel, the house of David, and the prophet Jeremiah were all chosen beforehand by God according to His eternal purpose.
According to the Bible, Jesus Christ was elected and appointed of God as the last Adam and the man through whom He would save humanity and reconcile all things to Himself, even before the world was made.
Also, by His foreknowledge, members of the church, which is the body of Christ were elected or chosen by God for Himself, for a special task, and destined to be glorified before the world began.
Even though, God has not made known what was in His foreknowledge that determined His elections in His Son Jesus, the Bible is clear that God's election is not partial, random selection, and neither is it upon any merits or holiness in the elected, but upon His own sovereign will and grace.
Further, the loving-kindness of God forbids that God would elect and predestine certain groups or individuals to eternal damnation.