I use this analogy. A salesman comes to your town and tells you that everyone in this town has a terrible, awful disease which no one knew about until this salesman shows up. Although the salesman can offer no proof of this disease he swears we will all suffer and die from it. However, he says the "good news" is he has the cure, and one can only get the cure from him, but he will save you and you will be eternally grateful to him if you but buy his product.
Meaning: Christians tell us that we all have sin and that sin will bring us a terrible awful fate. Nevermind that until they came along, no one ever suspected we had this terrible condition and the Christians can't offer one shred of proof that we have 'sin' or that a terrible fate awaits us. But, the 'good news' aka Gospel is they have the only cure and we can only get it from them - one can only be saved from sin and hell through Christ, not by living a good life or practicing peaceful Buddhism, etc. We are supposed to 'buy into' their product, i.e., believe it wholeheartedly (hook, line, and sinker) and accept Christ as our personal Savior and be eternally grateful to him.
The 'good news' only exists if one believes the premise of the 'bad news' that we have sinned and will be damned unless we accept their product. Sounds like a snake oil sales pitch to me. I think we in the town would do better to live like we did before Christianity came to town, before we had ever been accused of having the horrible condition called 'sin' which I have no reason to believe exists.
Oh, yeah, and the salesman tells those of us who are skeptical that even though he can't prove we have this deadly disease, we better not chance it, because if he is right that we have this disease and we did not accept the cure, it will be too late to buy his cure once we start experiencing the terrible fate.
How manipulative is that?!?!