If we knew for certain that there is an afterlife, we wouldn’t have great debates about it, and philosophers wouldn’t have spilled all that ink over the millennia wrangling over it. Since we don’t know, it makes more sense to assume there is no God and no afterlife, and act accordingly. That is, act as if what we do matters now. That way, we’ll think about the consequences of what we are doing.
(filling in for Randi on this week's Swift as The Amazing Bearded One continues to recuperate)
Hate to do this, but the existence of an afterlife and existence of The Invisible Incompetent Designer can be mutually exclusive. If in fact there is no afterlife then we are not warranted in concluding that there are no deities. And if in fact there are supernat heroes and supernat villains then we can't declare that one day we'll open our eyes(ockets) and find our bones and fossils touching base with them in some vanilla sky. Neither is contingent on the other.
In fairness to Shermer, Christian theology makes the two inseparable--it is the will of their schizophrenic deity that people clamber out their graves and get sorted into those who will take to the skies and those bound to toil in the underground mines. If there is no afterlife then the Christian deity does not exist (unless theologians and other suck-ups are willing to declare they were wrong about that premiss of theirs).
Needless to say, the delusional will always believe in things fantastical, irrational and for which there is no evidence. Those among them who believe the hereafter is going to land them six dozen virgins or get them cheek to cheek with their Almighty or get them hooked up with their dearly departed should tarry no longer and book a flight asap by jumping off the nearest cliff.