Last night I was having a conversation with some friends, and one of them asked me whether I believed in life after death. I hesitated, and then answered, "yes" because I do. I had hesitated because I suspect the existence we experience after death is so different from what we imagine, and our "identity" or "self" is so different in that existence, that it might not really be accurate to consider it the same life we have here continued into another place. That is, I don't expect to find us in a heaven such as is conventionally imagined or reported in some of the near-death-experiences.
The person I was speaking with asked me why I believed in life after death. I guess there are five reasons.
First is that I take some truths on authority, and the Authority I happen to trust is Mirza Husayn-Ali Nuri Baha'u'llah (1817-1892). Whatever signal is available to humanity from the Creator is usually somewhat garbled with noise, and so while I think some mystics and holy persons and spiritually enlightened figures have got the big picture right, I think they have lots of the details wrong. As a Baha'i, it seems to me that there was something extremely special about Baha'u'llah's perceptions and the Revelation that He gave humanity. His narrative (it's for the most part a standard Islamic narrative) about God communicating to people through a few special Messengers of God who receive Revelations makes sense to me, and He Himself (Baha'u'llah) fits into this narrative as a Messenger of God (whatever that means). I think the ratio of signal to noise in what Baha'u'llah gave us was very, very high.
Baha'u'llah did assure humanity that there was some sort of eternal nature in our individual human existence that would continue after death, although you have to look pretty hard through the English translations to find anything specific or anything that would justify a conventional belief in the sort of heaven that most folk religions promise their believers. As I understand the Baha'i Revelation, the emphasis stays on creating a heaven on earth in the present through practice of spiritual discipline (prayer, service, meditation, selflessness, kindness, love, etc.) I've considered the possibility that Baha'u'llah (and God) were essentially misleading us with a half-truth (the truth might be something like: God is all-knowing, so God knows all your thoughts, experiences, memories, feelings, and social connections, and since those things are essentially you, you are eternal in God's memory, and God is the only pure reality anyway, as what we experience is dependent upon God; however, your consciousness as an individual will cease at your death and your independent identity as a soul merges into a spiritual reality much as your body's atoms dissipate into the physical reality), but I now tend to discount that. It would be utilitarian gesture to spare us the misery and terror of death by letting is go on believing in a comforting afterlife or the eventual justice of the universe in post-death judgment, and as I look at this universe, I get the distinct impression God's morality is not utilitarian, and our comfort is not God's objective in this universe.
That said, religion as a human institution seems essential to keeping society in good order and helping us stay cohesive. Belief in a supernatural observer who can punish or reward us in this life and afterwards seems to do a lot of good in terms of helping convince people they shouldn't "cheat" and engage in unfair exchanges or take more than they give. I am sort of excited about the hypothesis that much of our recent evolutionary brain development was encouraged by cultural environments in which human groups that were able to engage in story-telling and organized religion were able to gain many advantages in fitness through enhanced cohesion and trust among their in-group. Organized religion requires an understanding of five levels of intentionality to get transmitted, and that requires significant brain work: I want (1) you to believe (2) in a supernatural being who hears our prayers and understands our desires (3) and therefore wants (4) to help us so long as we understand and obey (5) this supernatural being. The story-telling that goes along with religion also requires significant brain size. Our huge heads and large brains demand significant nutrition and complicate our pregnancies and births, so the pay-off must be pretty extreme.
Anyway, that's the first reason I believe in life-after-death. Baha'u'llah says such a thing is so.
The second reason I believe in life after death is reincarnation phenomena. I don't think we come back again as different people as standard reincarnation belief holds. Maybe that does happen, sometimes, or always, but I don't think so. It doesn't make sense to me. But, I have read Ian Stevenson's 20 Cases Suggestive of Reincarnation and I'm aware of some more recent cases that are even more convincing than anything in those 20 case studies. I don't know what is going on with memories of dead people getting transferred to children, but whatever it is, it seems to indicate to me that some forms of consciousness (such as memory) survive death, although I have no theory as to how some of these memories get "caught" by other people, or why there is a fairly low signal-to-noise ratio in the memories (children with the memories of other people who have died tend to remember many things with spectacular accuracy, even trivial details, but they also have lots of significant things they get wrong, or miss; the ratio of hits to misses is high enough to come out way ahead of any probability, but the misses are significant. I am actually open to the possibility that some forms of memory and consciousness exist independently of observable physical matter as we know it (not in our brains), as these would help explain shared hallucinations, telepathic entity encounters (seeing your friend in your room and then later learning the friend had been killed moments before you hallucinated seeing them). Reincarnation phenomena don't prove life after death, but they are a source of empirical evidence that some sort of continuation after death (at least of some of our memories and some of our feelings for other people) may be able to continue outside our bodies after death, at least for a while, and that is certainly suggestive.
The third reason I believe in life after death is the phenomena of living people having communication with dead people, most often through hallucinations (ghost encounters or spirit encounters). It's not just having hallucinations that suggest to me that there is some communication between living and the dead, it's the fact that in some exceptional cases this communication seems to offer information that doesn't seem to be available by any normal method to the person having the hallucination. This is probably only evidence for some sort of telepathy where information is transferred by means we don't understand and senses we don't know about, and then the recipient's brain invents the hallucination of the dead person as a bringer of this information in order to make sense of it. Yet, it might also be evidence for the survival of a will or conscious individuality of a person after death. Medium encounters with the dead also go in this category, although the ratio of signal to noise with mediums is very, very low (usually), and in fact most mediums are frauds. Yet, I think there have been some people who on some occasions seem to have received information in a supernatural way, and they claim it comes through the intercession of dead people. I'm also including encounters with saints, angels, and Mary the Mother of Jesus in this category of encounters with the dead. I understand that in some cultures the living and dead have regular communications, and it's hardly considered supernatural. Rather, it's considered normal. If we apply Occam's Razor I know this should all be taken as telepathy and positive hallucinations created by the unconscious, but I still take it as suggestive of life after death.
The fourth reason I believe in life after death is the phenomena of near-death-experiences. Yes, I know some people have been able to reproduce near-death-experiences in laboratories using drugs and electro-magnetic waves, and the correspondence of the experience to processes of death in the brain is also something I understand (e.g., life review as a result of the brain's ability to keep memories from flooding the consciousness being removed). Yet I don't ever see that finding physical correlates to spiritual or supernatural activities is an explanation for those spiritual or supernatural experiences, especially when the supernatural or spiritual experiences involve sensory perceptions and experiences that can be remembered later for which there is no explanation given our present understanding of physical reality. If something spiritual or supernatural happens to us, and we experience it physically (as we must), then there will be physical correlates of that experience. For example, if in meditation we "merge with the universe" I will of course expect the brain to show some sort of corresponding manifestation of shut-down in areas related to the sense of our body's position in space or the sense of self.
This raises the question of whether all "supernatural" experiences ought to have physical manifestations that can be studied scientifically. My expectation is that this universe is complete, and eventually after millions of years, or even billions of years, of science, there will be no "gaps" to fill with supernatural explanations. But I'm open to the possibility that some things in our reality are not ever going to be available for satisfactory study by the scientific method. I'm also open to the possibility that our ability to reason and use logic and math is also limited, or perhaps logic and math are themselves too limited, and so humans as we exist now are inherently incapable of understanding some aspects of the universe, just as an early hominid with a much smaller brain than ours might have been unable to understand third-order-intentionality (I know that you know that I know) or story-telling.
The fifth reason I believe in life after death relates to my intuition. I suspect we continue to exist because this answer feels right to me. I seem to perceive in some intuitive way that existence does not conclude at death. It seems likely to me that we do eventually cease to exist as individuals, and I suppose we may eventually merge into something better and transcendent to a point where our individuality is entirely lost, but I don't think that happens at death in the very literal way that our atoms disperse and go back into the earth and air, eventually to be consumed by the sun and then sent out into the vastness of space so that we physically merge with the universe.
One thing I dislike is when people who have no belief in life-after-death say that there is "no evidence" for it. I also dislike it when people who have religious beliefs say "it's something we take on faith" as if that was all there was to it. I think all human decision-making and belief comes to us through a mix of intuition and rational thought based on empirical observation. Of my five reasons for believing in life after death, three are empirical (reincarnation phenomena, communication with the dead / encounters with entities purporting to be the dead phenomena, and near-death-experience phenomena). My trusting in an authoritative source (my religious beliefs in Baha'u'llah and what He tells us) is not entirely based on faith; there is considerable empirical information about Baha'u'llah, and my understanding of this information informs my faith in Him and His message.
Everyone who believes with faith has at least some historical account of events that are supposedly actual events on which they base their faith. That is what makes a difference between belief in the Flying Spaghetti Monster from belief in God (at least the believe in God most modern education religious believers now have). Modern religious people understand very well that previous generations had different understandings of God, and yes, people "make" the Deity into forms they can relate to in their communal myth-making about God. The pre-modern tribal gods and the God of the Hebrew People of 2500 years ago is in some ways quite different from the God of Martin Buber or Hans Kung or Werner Heizenberg or Robert Bellah or Reinhold Neibuhr. I do not perceive that people keep worshiping different gods and inventing different gods. I think, rather, that Divinity has been understood or approached in different ways, according to the cultures and places and times. Human sophistication of understanding Divinity has been enhanced over time, especially recently, but the basic essentials of ethical and moral principles have always been a core of religion.
The best empirical evidence for atheism is the lack of scientific evidence for God, not the lack of empirical evidence for God. Empirical evidence (physical reality, history, personal experiences, the reports of others' experiences) informs our willingness to believe or disbelieve anything. Modern educated people face atheism and consider it. Certainly every modern educated person must know the basics of Ludwig Feuerbach's argument, or must consider, understand, and then reject the atheism of David Hume, Friedrich Nietzche, Jean-Paul Sartre, Peter Singer and so forth. The obnoxious and pugnacious internet trolls advocating atheism and the proselytizers for the alternative religion of empirical materialism and Scientism also present challenges to believers. Many educated people who retain their faith do so not simply because
they have faith, but also because the evidence and argument presented by
such atheists remains for them unconvincing. Among the most brilliant people with the most training and the strongest minds, a great many continue to believe in God and life after death.
This probably presents me with a sixth reason for believing in life-after-death, and that is the power of the desire to conform and meet social expectations. Yet in my circle of friends there are very many non-religious persons and even several atheists, and among the believers there are very few who share my Baha'i Faith. One thing I like about the Baha'i Faith community (and also Unitarians, New Age believers, and that sort of thing) is the seemingly high rate of eccentric people. Eccentric people tend to be less susceptible to conformity bias, and I like to think that people believe in a religion because they really believe it, and not because social pressures to conform have subtly shaped their thinking so they came to believe in order to go along with what others were doing.