But while I believe Jesus died for all of mankind, I do not believe He paid the penalty for all sin. In Matthew 12:22-32, Jesus healed a man who was demon-possessed, blind and unable to speak. Seeing this, the people asked, "Is not this the Son of David?" The Pharisees immediately responded by claiming Jesus had acted in the power of Satan. The opposite was true; Jesus was empowered by the Holy Spirit (v. 28). The Lord told them that all sin could be forgiven but one: the blasphemy of the Holy Spirit (v. 31-32). It is the one sin Jesus' death does not cover.
Blasphemy of the Holy Spirit is the rejection of the work of the Holy Spirit as evidence that Jesus is both Israel's Messiah and the Son of God (Jn. 1:41; 3:14-18; 16:7-15). Whether it be by rejecting the miracles done at the hand of Jesus, rejecting the miracles done by His apostles, or by rejecting the miraculous Gospel message we share with lost souls, man condemns himself to an eternity of darkness and misery because he is, in effect, calling the Holy Spirit a liar.
While I cannot prove this, I believe that at the Great White Throne Judgment (Rev. 20:11-15), each person's life will be judged according to "the books" (I believe this refers to the Books of the Bible). All will be found guilty, for all have sinned (Rom. 3:23). Then the Judge will look in the "Lamb's Book of Life" which has the names of all those who accepted Jesus (Rev. 13:8). Those who rejected the evidence provided them by the Holy Spirit, having failed to accept Jesus, will not have their names in His book. They will be cast into the Lake of Fire; not for their sins, but for failing to accept God's Son!
If you believe in Jesus, it is because the Holy Spirit convinced you!