God Himself supplies the necessary condition to come to Jesus, that's why it is 'sola gratia,' by grace alone, that we are saved.
R. C. SproulUnbelief is judged by Jesus not as an intellectual error but as a hostile act of prejudice against God himself.
R. C. SproulThe great triad of enemies for Christian growth contain the world, the flesh, and the devil.
R. C. Sproul