It is of his own decrees, of what before the worlds began he decreed that he would do.
God then acts later in time according to his (fore)knowledge of those decrees.
Before time, God decreed to elect specific persons in time to become children of God, to be born of him (Jn 1:13).
Their election in time is according to God's foreknown decree before their birth to do so; i.e., "according to God's foreknowledge."
Greetings Eleanor,
We will be very close to each other, so, I'm thinking is it even worth discussing, because this is a classic equifinality of a doctrine.
While I whole heartily agree God Is Omniscient. He knows everything; everything possible, everything actual; all events, all creatures, of the
past, the present, and the future. He is
perfectly acquainted with every detail in the life of every being in heaven, in earth, and under the earth. "He knoweth what is in the darkness" (Dan. 2:22). Nothing escapes His notice, nothing can be hidden from Him, nothing is forgotten by Him. Well may we say with the psalmist, "Such knowledge is too wonderful for me; it is high, I cannot attain unto it" (Ps. 139:6). His knowledge is perfect. He never errs, never changes, never overlooks anything. "Neither is there any creature that is not manifest in his sight: but all things are naked and opened unto the eyes of him with whom we have to do" (Heb. 4:13). Such is the God with whom we "have to do"!
I'm very much aware that some pseudo Bible teachers pervert His foreknowledge to set aside His unconditional election unto eternal life.
When the blessed subject of divine foreordination is expounded, when God’s eternal choice of certain ones to be conformed to the image of His Son is set forth,
the enemy sends along someone to argue that election is based upon the foreknowledge of God. This foreknowledge is interpreted to mean that God foresaw certain ones who would be more pliable than others and they would respond more readily to the strivings of the Spirit. So, because God knew they would believe, He predestinated them unto salvation. It is a perversion of God's word. It repudiates the truth of total depravity
, for it argues that there is something good in some men. It takes away the independency of God, for it makes His decrees rest upon what He discovers in the creature, as if many have some good, power to love and serve God,
apart from God causing them to do so.
It completely turns things upside down, for in saying God foresaw certain sinners who would believe in Christ, and because of this He predestinated them unto salvation,
is the very reverse of the truth. Scripture affirms that God, in His sovereignty, singled out certain ones to be recipients of His distinguishing favors (Acts 13:48); therefore He determined to bestow upon them the gift of faith
. False theology makes God’s foreknowledge of our believing
the cause of His election to salvation. However, God’s election is the cause, and our believing in Christ the effect.
It should, however, be pointed out that God’s knowledge, or His cognition
of the future,
considered simply in themselves,
does not mean His foreknowledge has nothing to do with his decrees as not the causative~as I said above, God knew that unless he had an election by grace, before anyone had done any good or evil, then no one would have ever come to love, serve God by their own power when left to themselves, none, including the angels.
God's foreknowledge and His decrees are not one and the same, even though they may be very close~God did not decree the wicked to do evil, but knew that he would, base on his infinite knowledge of all things, and knowing that He alone is immutable, an attribute that he alone possess~as I said above: "God Is Omniscient. He knows everything; everything possible, everything actual; all events, all creatures, of the past, the present, and the future, nothing can escape his perfect knowledge, not one single thing, impossible. 
