At the end of the day, are threats of the afterlife the best argument that a Christian has?

I've had debates with Christians, and when they fail to convince me of the love of a potential God or in my case the utility of such things some of them present the possibility of a dreary afterlife scenario that awaits non believers. While I know that not all people believe out of fear of this, at least a lot of them do. At the end of the day, are the best arguments nothing but threats of a non demonstrable world of torment? The rationale behind the other aspects of the religion just don't seem to work with people who think outside of the box.