It seems that atheists have their hearts hardened by the thought of God and gets harder as time goes on. I think it is a process that God affects everyone. Hearts are changed by all. The hearts of those who fear him turn toward him and those who hate him turn away. The more we are exposed the more we either harden or soften. Its a our reaction to God that causes change.
Exactly. We have free will. He knows what is to come as the result of our rebellion, but we own the responsibility.