Greg Boyd gives an excellent review of Harvard neurosurgeon Eben Alexander's Proof of Heaven: A Neurosurgeon's Journey into the Afterlife.
Greg affirms a number of things, and then, as a theologian, gives five concerns. For example, Alexander says he was given, in his afterlife experience, three messages which he is to communicate to the world: “You are loved and cherished;” “You have nothing to fear;” and “There is nothing you can do wrong.” Greg responds:
"For obvious reasons, the third one concerns me. Indeed, it strikes me as utterly absurd. I have trouble believing that Alexander believes that if someone raped his child, for example, it wouldn’t be “wrong.” But though I’ve tried to think of ways to interpret this statement such that it wouldn’t imply this, I have so far failed. If a divine agent gave this teaching to Alexander with the meaning that there is no such thing as evil and sin, then I have no choice but to conclude that this agent was demonic."