Free will and forknowledge and thier doctrines have been debated for a long time, with various views being professed in various ways, from Augustine, to Aquinas to Luther, to Clavin and beyond.
Fact is we don't KNOW how God works but that doesn't stop as from trying to figure it out, LOL!
Here is a great book for those that are really interested in what Christian theology says about this and other matters:
Christian Theology: An Introduction by Alister E. McGrath ( Paperback - Oct 12, 2010)