Just In Case Fallacy / Worst Case Scenario Fallacy occurs when the worst case scenario is used rather than the most likely scenario in making an argument.
Bill Nye arguing against Creation science: "What keeps the United States ahead, what makes the United States a world leader, is our technology, our new ideas, our innovations. If we continue to eschew science, eschew the process, and try to divide science into observational science and historic science, we are not going to move forward, we’ll not embrace natural laws, we’ll not make discoveries, we’ll not invent and innovate and stay ahead."
Rocky: "God is a just God. He is an absolutely holy God. He must judge sin. By your own admission, you have stolen, lied, and committed adultery. If you were to die tomorrow, would the just and holy God judge you worthy of Heaven or of Hell?"
Sandy: "This is an example of the worst case scenario fallacy. Hell probably doesn't exist. God probably doesn't exist. I'll take my chances."
Rocky: "When you talk of probability, can you share your math?"
Sandy: "I didn't do the math myself but a book on logic implied that Hell probably doesn't exist. They didn't tell how they did their math."
Rocky: "I know, by Divine revelation, that Hell does exist. The probability of Hell being nonexistent is exactly zero. It's real and you don't want to go there. The probability of you going to Hell if you choose to reject Jesus Christ is exactly 100 percent. However, if you come to Him merely to avoid Hell, He isn't really interested in that. He is looking for those who will love Him and obey Him. That is why He created you. And that is the only place where a human being can find peace and satisfaction."