Since there are different phases of salvation, justification, judgment, and atonement, there are also different phases of forgiveness and pardon. All mankind was, in a certain sense, forgiven at Calvary and placed under probationary grace. This is the meaning of 2 Corinthians 5:19: "To wit, that God was in Christ, reconciling the world unto Himself, not imputing their trespasses unto them." In all of the 6,000 years of earth's history, God has never imputed our sins to us, not even a single one to a single individual. He has imputed all of our sins to His only begotten Son. Thus, we were born forgiven.
We may all say with the Psalmist, "Behold, I was shapen in iniquity and in sin did my mother conceive me" (Psalm 51:5). We were all conceived in sin, yet we were born forgiven. God forgave us before we even realized our need for forgiveness. This good news applies to the whole world. God has not imputed sin to any of us. If He had, we would be dead. Thus, we conclude that the whole world has been, in a certain sense, forgiven of all of their sins, except for one. Whoever blasphemes the Holy Ghost "shall not be forgiven" (Matthew 12:31). "He that believeth not shall be damned" (Mark 16:16). For this reason, many will be lost. And it is not because Jesus did not redeem them "from the curse of the law" (Galatians 3:13). He "is the Saviour of all men" (see John 4:42, 1 Timothy 4:10, 1 John 4:14).
"Christ died for our sins" (1 Corinthians 15:3). The good news of the gospel is for everyone. He has died for everyone's sins. Yet the plan of salvation stands free of logical contradictions and unjust machinations. The death of Christ for the sins of the whole world is actual and not merely provisional. "We have now received the atonement" (Romans 5:11). The first phase of the atonement is complete and effective for everyone. "All alike are justified" (Romans 3:24, NEB). Nevertheless, the plan of salvation does not conclude in a form of double jeopardy. A sin does exist for which Jesus did not die. A clear understanding of the unpardonable sin resolves all the difficulty and makes the gospel very easy to understand.