The new birth comes by sovereign action.

"I remember that sacred time when the Spirit regenerated me, though I understood nothing of the theology of it. One day my mind was dark to the gospel and things of God; the next, it was as though a floodlight came on and I saw what I'd never been able to see and understood what had always been a fog to me. My desires the day before were wholly self-centered; the next day, my heart melted at the things of God and inclined toward Christ. The way that I looked at everything changed from that moment. I believed the gospel; I put my trust in Christ; I committed myself to be His follower. But none of this happened until the Holy Spirit turned on the lights in my darkened mind and soul. I did not even understand enough before this to ask the Lord to regenerate me! He just did it; then I believed the gospel. That's why the use of the passive voice in "born again" is critical for us to grasp? The new birth comes by sovereign action." - http://www.southwoodsbc.org/sermons/john_03.01-08.html