"Could you be wrong in your claims about Judgment Day and the existence of hell?"
The existence of hell and the surety of the judgment are not the claims of fallible man. The Bible is the source of the claim, and it is utterly infallible. When someone becomes a Christian, he is admitting that he was in the wrong, and that God is justified in His declarations that we have sinned against Him.
However, let’s surmise for a moment that there is no Judgment Day and no hell. That would mean that the Bible is a huge hoax, in which more than forty authors collaborated (over a period of 3,000 years) to produce a document revealing God’s character as "just." They portrayed Him as a just judge, who warned that He would eventually punish murderers, rapists, liars, thieves, adulterers, etc. Each of those writers (who professed to be godly) therefore bore false witness, transgressing the very commandments they claimed to be true.
It would mean that Jesus Christ was a liar, and that all the claims He made about the reality of judgment were there-fore false. It would also mean that He gave His life in vain, as did multitudes of martyrs who have given their lives for the cause of Christ. Add to that the thought that if there is no ultimate justice, it means that the Creator of all things is unjust—that He sees murder and rape and couldn’t care less, making Him worse than a corrupt human judge who refuses to bring criminals to justice.
Here’s the good news, though, if there is no hell: You won’t know a thing after you die. It will be the end. No heaven, no hell. Just nothing. You won’t even realize that it’s good news.
Here’s the bad news if the Bible is right and that there is eternal justice: You will find yourself standing before the judgment throne of a holy God, who has seen every sin you have ever committed. Think of it. A holy and perfect Creator has seen your thought-life and every secret sin you have ever committed. You have a multitude of sins, and God must by nature carry out justice. Ask Him to remind you of the sins of your youth. Ask Him to bring to remembrance your secret sexual sins, the lies, the gossip, and other idle words. You may have forgotten your past sins, but God hasn’t. Hell will be your just desert (exactly what you deserve), and you will have no one to blame but yourself. This is the claim of the Bible. If you don’t believe it, it is still true. It will still happen.
Yet, there is good news—incredibly good news. We deserve judgment, but God offers us mercy through the cross. He paid our fine so that we could leave the courtroom. He destroyed the power of the grave for all who obey Him. Simply obey the gospel, and live. By doing that you will find out for yourself that the gospel is indeed the "gospel truth." Jesus said that if you obey Him, you will know the truth, and the truth will make you free (see John 8:31,32).
Get on your knees today, confess and forsake your sins. Tell God you are truly sorry, then trust the Savior as you would trust yourself to a parachute. Then you will find yourself in a terrible dilemma. You will know for certain that hell is a reality. When you get up the courage to warn people you care about, they will smile passively, and say, "Could you be wrong in your claims about Judgment Day and the existence of hell?"