Christian exclusivism or particularism is roughly the view that God's particular revelation has been done in Jesus (and only in Jesus). On the contrary, religious pluralism is the view that God's revelation has been done in several (not just one) religious traditions. (This has implications for "salvation": If exclusivism is right, "salvation" is possible in just one source; if pluralism is right, "salvation" is available in more than one source).
Most Christians are exclusivists. But some Christians are pluralists. (Even though I agree with exclusivists that Jesus' self-perception was exclusivist, not pluralist, some disagree). For example Marcus Borg is a Christian religious pluralist, summarizes the difference between Christian exclusivism and pluralism like this: "Imaging Jesus as a particular instance of a type of religious personality known cross-culturally undermines a widespread Christian belief that Jesus is unique, which commonly is linked to the notion that Christianity is exclusively true and that Jesus is "the only way." The image I have sketched views Jesus differently: rather than being the exclusive revelation of God, he is one of many mediators of the sacred. Yet even as this view subtracts from the uniqueness of Jesus and the Christian tradition, it also in my judgment adds to the credibility of both."
The Christian religious pluralist, like Borg, considers that Jesus was not unique, but that he belongs for a kind of "spiritual teachers" known cross-culturally. In other words, God's revelation has not been limited to just a person, but to a whole group of individuals. (Note that Borg is not saying that ALL spiritual teachers are alike; rather his point is that, like Jesus, there are OTHERS who share the same condition as "mediators of the sacred".)
In the case of Borg, I think his own mystical experiences and concept of God have strongly influenced his view about Jesus (see full discussion here). After all, Borg doesn't share the concept of God as a personal being which is trascedent regarding the universe (a concept essential in monotheism). Borg's concept of God is not Christian, but a kind of impersonalistic panentheism rooted in his own mystical experiences which "gave me a new understanding of the meaning of the word God. I realized that God does not refer to a supernatural being 'out there' (which is where I had put God ever since my childhood musings about God 'up in heaven'). Rather, I began to see that the word God refers to the sacred at the center of existence, the holy mystery that is all around us and within us"
The personalistic conception of God as a supernatural (non-natural, non-physical) being "out there" (i.e. ontologically objective and trascendent) is explicitly denied by Borg. In its place, it is put a non-personal, mysterious entity which is inmanent to the world, an entity which is "at the center of existence".
Note that Borg's concept of God makes religious exclusivism almost impossible. After all, why and how so an impersonal entity like that can "choose" a given person as the only intermediary to the sacred? But if you accept a personalistic concept of God, then you cannot rule out that such personal being choose (over all others) a specific person (e.g. his "Son") as the exclusive, unique and ultimate revelation of God. The latter is the Christian exclusivistic view (which coheres with the personalistic conception of God).
But in this post, I won't comment on Borg or panentheism, but in how the evidence from parapsychology, religious experiences and near-death experience is compatible, or not, with Christian exclusivism in the context of 3 typical arguments by pluralists.
3 common arguments from religious pluralists:
1-Jesus' resurrection cannot justify his exclusivism, because many people who have been clinically dead have woke up (i.e. coming to life again), for example in near-death experiences or in other cases (e.g. waking up in the morgue).
This is the worst of the pluralistic arguments, because it is rooted in a very common and egregious conceptual confusion. All the examples known of people who have returned to life (e.g. in NDEs or in the morgue) are examples of RESUCITATIONS AND REVIVIFICATIONS, not of resurrections in the particular ontological sense in which it applies to Jesus.
In the case of Jesus, he rose from the dead in the same body which is transformed into a immortal body (this is why there is not historical evidence of Jesus dying for a second time). In the case of resucitations and revivifications, these people came to life in the same mortal body, so they will die again. And in fact they die again (e.g. Jesus rising Lazarus from the dead was an example of resuscitation, not of resurrection).
On the other hand, the argument by most Chrstian exclusivists is not that Jesus' resurrection (in the above, technical, theologically relevant sense) by itself justifies exclusivism: Rather, such a event has to be interpreted in the context of Jesus' own teachings, which includes references to his divine exclusivity (see discussion and evidence here). (Note that it doesn't exclude that Jesus' nature and the plausibility of his teachins be interpreted in the context of his resurrection too: After all, the resurrection "tells us something" about the nature of Jesus and hence about the possible authenticity of his radical claims about himself).
So, Jesus' authentic exclusivistic teachings + his bodily resurrection (which has not precedent in history) justify the conclusion that exclusivism is true. (Otherwise, we would have to think that Jesus was deluded or was lying, and in both case we wouldn't expect a resurrection of a person like that).
Also, if pluralism is true, then why we don't find good evidence for resurrections (not resuscitations) in other spiritual teachers who supposedly stand in the same level than Jesus? We find in them paranormal deeds (this is something in common with Jesus), but not such an unique event like the resurrection. Precisely, the unique or special nature of the resurrection coheres with the unique and special character, nature and teachings of Jesus, and this is what we would expect if Jesus' exclusivism is true.
2-Near-death experiences and religious experiences suggest that people of all the religions, and even atheists, sometimes tend to experience images, symbols, deities proper of their religions, or the feeling to be in the presence of God. Hence, NDEs refute Christian exclusivism because it shows that non-Christians can be saved too.
Again, I find this argument surprisingly weak and superficial:
a)It misrepresents the Christian doctrine of exclusivism. This doctrine is not incompatible with the fact that non-Christians will feel temporarily "happy", or will feel "God's presence" or "God's love" in the afterlife (According to the Christian doctrine, God loves all of us, even bad people. Judgment by God has to be with God's justice, not with God's inconditional love. Anti-Christian people often conflate this too, because they interpret God's judgment as a denial of God's love, when actually God's judgment has to be considered in light of his perfect justice).
Exclusivism refers to the view that Jesus is the only or unique intermediary between God's particular revelation and human beings, specially regarding salvation. (It has nothing to do with subjective positive or negatve feelings of spirits in the afterlife).
It could be say by the pluralist that these experiences refute exclusivism in the sense that if Christianity were true, we would expect non-Christian people to go to hell, instead of feeling God's intense love and extreme happiness.
But this reply conflates Christian exclusivism with the doctrine of hell. At most, the pluralist's rejoinder (if correct) will show that the doctrine of hell is false, not that pluralism is true. (After all, exclusivism could be true and the doctrine of hell be false. Perhaps nodoby will go to a "hell" in the sense in which traditional Christianity portraits it, but perhaps such non-Christian people won't enjoy fully God's full eternal salvation either).
Note that if "everybody" is saved (regardless of whether they are Hitlers, Ghandi, terrotists, Christians, atheists, etc.) then it is hard to see which is the point of the concept of "salvation" (which has been taught, in different ways, in many religious and spiritual traditions) and the existence of "many spiritual teachers" (who in addition to teaching common doctrines with other teachers, also teach particular doctrines at variance with each other). If our fate were the same for all the people, our current lives and behaviour are ultimately irrelevant and we can freely to be bad and mean, we can kill other people and be selfish, because we know that we will be saved too. This view seems to be very unjust and not fair. If God exists, we would expect in Him to be fully just.
Finally, the afterlife research provides some evidence for something like a "hell" (see this Victor Zammit's article here), so it is not clear that such Christian doctrine (or something like it) is wholly false.
Moreover, there ARE testimonies of people with near-death experiences who have reported to go the "hell" or something like this:
Wishful thinking is not allowed here. If the hell exists or not is a factual question, not a topic that we have to settle on the grounds of our wishes.
b)The pluralist argument also assumes (selectively) that all the relevant NDEs (ore religious experiences) with pluralistic contents are veridical regarding the spiritual/religious content of the experience. Obviously it is far from clear. Current investigation in NDEs has shown, at most, that a materialistic explanation of the experience (specially of the veridical information of the enviroment reported by some NDErs) is weak and insufficient, hence justifying the dualistic interpretation that consciousness survives death as the best explanation. But arguing from there to the conclusion that all the contents (specially the theological contents relevant to the problem of salvation) of these experiences is also veridical is a huge extrapolation without any independent evidence (besides the testimnony of the experiencers).
The problem with this is that it infers from the plurality of the contents of religious experiences in the afterlife to the conclusion that pluralism is truth regarding SALVATION (which is clearly a non-sequitur).
You can have plurality of contents in religious/spiritual experiences and just ONE actual way to salvation. Both of these propositions are not mutually contradictory.
In order to see the problem with this, think carefully about the following: In mystical experiences (like Borg's), many mystics feel "connected to all what exists", or that "the universe is one with me", the "self is an illusion", the "Tao is beyond words and reason", "individuality is an illusion which fuses into pure consciousness", "all are one" or (in Borg's own description) "God is more than everything, and yet everything is in God" and other phrases implying ontological impersonalism. Not surprisingly, these mystics tend to be atheists regarding the Christian God or theism in general (which conceive God as a trascendent person different and ontologically senior to the universe) and often are sympathetic to pantheism (and spiritualitic versions of the impersonalistic worldviews which I've criticized elsewhere).
If the Christian view is right, the fabric of reality is radically PERSONAL (God + a bunch of created spirits and realities created on behalf of these spirits), but if radical impersonalistic-mystical views are true, then the Christian view is false. Note that we know (on purely analytical, logical grounds) that one of them HAVE to be false. They cannot be both true because they exclude each other.
Provided you respect logic, you cannot simply say that the mystical experiences of mystics are "so valid" as the Christian view (and hence that exclusivism is false), because it is logically impossible. The mystic has to argue that the Christian conception of God is false, and the Christian will have to argue or believe that the mystic's experience is either delusional, false or (if true) incomplete. (Some Christian philosophers have argued that mystical experiences are real, but they reveal just some aspects of the self, not of God).
Now, if on a priori grounds we know that both accounts cannot be fully true, then how the hell is it going to change if the experience in question is given in a NDE? Even in the afterlife, both experiences are logically imcompatible (and the fact they're produced in an afterlife doesn't automatically makes them both true) because they imply mutually exclusive propositions (radical ontological impersonalism in some mystical experiences; and radical ontological personalism regarding the self and God in the Christian view).
In summary, since many religious experiences have contents which are logically incompatible with the contents of other religious experiences, it follows as a matter of logical necessity that at least ONE of them is false.
Therefore, the fact that people have different sincere religious/spiritual experiences either in this life (e.g. mystical experiences) or in the afterlife (e.g. NDEs) is not, by itself, an argument for religious pluralism regarding salvation.
3-Jesus performed miracles and according to parapsychology many people can perform amazing deeds which are pretty similar.
Again this misrepresents Jesus' exclusivism. His exclusivism doesn't exclude that OTHER people can perfom amazing paranormal feats (his is not a "paranormal exclusivism"). Rather, Jesus' exclusivism is connected with his ontological nature and teachings about God's kingdom, revelation and salvation, not with particular deeds like mind-reading, blending spongs, moving balls with the mind, or healing some diseases with our hands (presumibly Jesus could do all of these things and many others which, by the way, are far beyond than what an Uri Geller or yogui could do, like walking on the water or multiplying foods or making exorcisms on his own authority).
This theological topic is not a matter to be settle on the grounds of parapsychology and afterlife research alone (which are theologically ambiguous), you have to study with an open and critical mind the evidence for and against Jesus' life, his teachings, his resurrection and other religions too. This is a complex topic, which demands on you hard thinking, constant self-criticism (regarding your bias and wishful thinking), logical thinking and intellectual honesty.
I'm still walking in this journey...