I think that C.S. Lewis states the dilemma of Election and Free Will quite accurately in his book The Silver Chair. He outlines the basic question of how can they both be present and then describes how it is so in a conversation between Jill and Aslan. Jill wonders how Aslan could say he called her when she called him. Aslan begins,
“”But your task will be the harder because of what you have done.”
“Please, what task, Sir?” said Jill.
“The task for which I called you and him here out of your own world.”
This puzzled Jill very much…
“I was wondering – I mean – could there be some mistake? Because nobody called me and [Eustace], you know. It was we who asked to come here. [Eustace] said we were to call to [you]… and perhaps [you] would let us in. And we did, and then we found the door open.”
“You would not have called to me unless I had been calling you,” said the Lion.”¹
In this excerpt Aslan describes how he calls us when we call him. It is a wonder at the complicity of this concept yet, Lewis does a wonderful job at showing the simplicity of the real matter. It is God who calls us and so we call to him with our own free will.
¹ – C.S. Lewis, The Silver Chair pp. 22-23 [Italics added for purpose of highlighting topic]