Romans 8:29 For whom he did foreknow, he also did predestinate [to be] conformed to the image of his Son, that he might be the firstborn among many brethren.
Foreknow in the greek "proginosko" => to have determined beforehand. To foreknow those whom God elected to salvation. To determine in advance those that God had chosen.
Examine at I Peter 1:2
I Peter 2:1 Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.
In I Peter 1:2 the word foreknowledge in Greek is prognosis or to pre-arrange.
Somehow some christians take these verses out of context and use and apply it in their doctrine with devistating results. The consequences of saying that God looked down and saw man's good choice to select God and then God elected them is a works based salvation. Man did something good (chose God) and God rewards him for his actions with Salvation
Christians, preachers and teachers, learned men of God cling to this wrong teaching. Saved by Grace through Faith but you still throw out this definition of foreknowledge you just threw out the Sovereignty of God and put man in Control of Salvation.