C.S. Lewis emphasizes freewill very heavily, but you cannot go to that much of an extreme. I will not negate that fact that we have freewill. Jesus says, "Come follow me," implying that the disciples had a choice in following him." It is written chose this day whom you will serve...", indicating we have a choice whether to serve God or not on a daily basis. Nonetheless, freewill taken to Lewis' extent implies that I have done something to become saved. If I have chosen God, instead of God choosing me, then it is of my own doing, it not of His grace and mercy.