There is a (not so) surprising trend in contemporary epistemic justifications for faith among postmodernists today. Much of postmodern apologetics takes an aprioristic approach to spiritual experiences, presuming that their occurrence constitutes (in some sense) "proof" of an ontological reality.
For these eager religionists, experiences are unquestionably valid without entertaining the possibility that they are potentially the result of neurological processes with no supernatural origin whatsoever. Although postmodernists do not believe they can eliminate all religious doubt, their apologetic stratagem still considers faith in religion (or God or whatever) justified almost entirely from subjective interpretations of supposed “spiritual” encounters. Describing divine phenomenality appears naïvely to presume that questions of legitimacy would largely dissipate if the nonbeliever had an “excessive” encounter with what they perceive to be supernatural.
The most definitive characteristic of postmodern apologetics is its rejection of offering “proof” for Christian theism in a way that acquires universal agreement. In actuality, however, postmodern apologetics practices a qualified form of evidentialism once they appropriate new phenomenology. Edmund Husserl explains that a first-person account of an experience constitutes “evidence” for the experience’s authenticity. He writes,
“In an extremely broad sense, an ‘experiencing’ of something that is, and is thus; it is precisely a mental seeing of something itself.”
Consequently, the act of experiencing (“a mental seeing”) translates into a first-person testimony that allegedly corroborates the veracity of an individual’s subjective interpretation. Phenomenological apologetics professes to offer “objective” truth but only in so far as intersubjective experience (i.e. the interconnectivity of numerous subject-object relationships) is its foundation.
“When we say that something is ‘objectively true,’ we mean that we all experience it in the same way, which makes it transcendentally true (since it transcends any particular experience). Ultimately, Husserl’s overcoming of subjectivism, relativism, and reductionism is because of the intersubjectivity that makes transcendence a reality.”
By admitting the prospect of mysticism, new phenomenologists still desire a sense of evidential credibility to substantiate their experiences. From a psychological standpoint, the idea that subjective occurrences provide “evidence” is not surprising since heightened emotional arousals tend to concretize an individual’s already-established belief system. Known as the “feelings-as-evidence hypothesis,” so-called divine encounters could signify “empirical” evidence for the experiencer. Nevertheless, there is nothing about an encounter’s phenomenality that corroborates orthodox Christianity; it can only suggest its possibility.
The most prevalent failure of postmodern apologetics is its lack of sustainable criteria for evaluating the validity of its supernatural conclusions. Regardless of how “genuine” these divine encounters are for the individual, they should not preclude critical scrutiny of their supposed authenticity to the point that it deters falsification entirely. As Gordon Lewis remarks,
“Our primary concern is to know whether Christianity is true, and if so, on what grounds. If we support its truth-claims primarily from mystical experience, we are immediately faced with a problem. Enthusiastic testimonies of mystics support religions with truth-claims contradictory to Christianity’s.”
Merely claiming to have encountered God is not a sufficient reason to believe that a person has accurately identified, described, and interpreted the occurrence. Thus, insisting on independent criteria to evaluate religious claims is not a demand for God to submit to human rules, philosophy, or language. Instead, independent criteria are meant to authenticate the human claims about God by requiring substantive credentials for authenticity and accuracy.
Even philosophical phenomenology admits that the experiences of human consciousness do not imply accuracy about the experience itself. Hence, appeals to spiritual experiences still demand a universality in order to make it comprehensible and relatable to other persons, as well as a methodology for verifying its supernatural origin. Postmodern apologetics merely replaces one form of a self-legitimizing description of reality (“metanarrative”) for another form of a universally self-authenticating story (“mysticism”). The major problem is that supposed spiritual experiences are neither self-validating nor self-interpreting. Moreover, research into spiritual experiences from the cognitive and neurosciences has provided natural explanations for their manifestation without speculating about a supernatural origin. In fact, individuals can self-induce or artificially manufacture even the tremendously overwhelming characteristics of “divine excess” through psychotropic drugs, such as psilocybin.
Remarkably, postmodern apologetics may actually provide the necessary phenomenological claim essential for the average person to become at least marginally intrigued with Christianity. Psychologically, the “affect-as-information model” suggests that individuals oftentimes construct their beliefs chiefly from experiential information events. Experiential knowledge frequently overrides indirect propositional assertions or abstract concepts. Thus, people will likely never accept anything that conflicts with their personal experiences. The widespread mundaneness of these “spiritual” encounters, however, makes their apologetic value hollow from both an objective and subjective standard. Phenomenologically, apologists can only describe their personal experiences but cannot establish a reasonable basis for interpreting them as supernatural. This limitation is because phenomenology seeks to identify and articulate only the phenomena as it presents itself to human consciousness, which is a person’s relationship to the phenomena instead of a mental representation or objective analysis of the phenomena itself. Apologetically, the appeal to spiritual experiences merely constitutes a defense of the individual’s privatized estimation, something that postmoderns emphasize is too socio-politically encultured to be sensibly reliable.
Nothing about these experiences suggest that their interpretation is valid or that the truth-claims of orthodox Christianity are justifiable. As one postmodernist admits,
“All our experience, and particularly our religious and moral experience, is culture-dependent. The majesty of the world that surrounds us will evoke a different experience in a Christian, an adherent of African Traditional Religions, a Hindu or an atheist.”
In other worlds, it is the already accepted worldview that determines a person’s interpretation of these experiences, making postmodern apologetics little more than the rationalization of an already-held belief system. Even Westphal acknowledges that there is no method from which to derive authentic knowledge about God, regardless of its rationality or subjectivity. Due to the finite and contingent nature of humanity, as well as the noetic effects of sin, a genuine postmodern apologetic should likewise oppose any effort to make knowledge of God, or God himself, reliant on human interpretations of mystical experiences.
“The element of truth is that no one can deny that mystical experiences as psychological phenomena have occurred. But the fallacy is the implication that therefore no one can challenge a particular interpretation of the experiences….mystics may misinterpret their experience.”
 See for example, Patrick McNamara, The Neuroscience of Religious Experience (2009; repr., New York: Cambridge University Press, 2014).  Cf. William Lane Craig, Reasonable Faith: Christian Truth and Apologetics, 3rd ed. (Wheaton, IL: Crossway Books, 2008), 47-51.  Simmons and Benson, The New Phenomenology, 200.  Edmund Husserl, Cartesian Meditations: An Introduction to Phenomenology, trans. Dorion Cairns (The Hague, Netherlands: Martinus Nijhoff, 1960), 12; emphasis in original.  Simmons and Benson, The New Phenomenology, 25.  Gerald L. Clore and Karen Gasper, “Feeling is Believing: Some Affective Influences on Belief,” in Emotions and Beliefs: How Feelings Influence Thoughts, Pbk. ed., ed. Nico H. Frijda, Antony S. R. Manstead, and Sacha Bem, Studies in Emotion and Social Interaction: Second Series (New York: Cambridge University Press, 2000), 10-44.  Cf. Simmons and Benson, The New Phenomenology, 134-35, 171.  John Warwick Montgomery, Faith Founded on Fact: Essays in Evidential Apologetics (Nashville, TN: Thomas Nelson, 1978), 40; Brian Hebblethwaite, “The Nature and Limits of Theological Understanding,” in The Nature and Limits of Human Understanding, ed. Anthony Sanford, The 2001 Gifford Lectures at the University of Glasgow (New York: T&T Clark, 2003), 240-44; Clark, Dialogical Apologetics, 23-24.  Gordon R. Lewis, Testing Christianity’s Truth Claims: Approaches to Christian Apologetics, Pbk. ed. (1976; repr., Chicago, IL: Moody Press, 1980), 169-70.  Ibid., 203.  Simmons and Benson, The New Phenomenology, 17.  Cf. Christina M. Gschwandtner, Postmodern Apologetics? Arguments for God in Contemporary Philosophy, Perspectives in Continental Philosophy (New York: Fordham University Press, 2013), 209.  Kenneth D. Boa and Robert M. Bowman Jr., Faith Has Its Reasons: Integrative Approaches to Defending the Christian Faith, 2nd ed. (Downers Grove, IL: InterVarsity Press, 2005), 176-78.  James Pratt remarks, “Mysticism, therefore, like everything else, is to be accounted for solely by the laws of a scientific psychology, and its source is to be sought in the individual mind and in society. Imitation, social education, and individual suggestion furnish a quite sufficient explanation for all the phenomena of mysticism” (James Bissett Pratt, The Religious Consciousness: A Psychological Study, Sacred Texts [1920; repr., New York: Cosimo Classics, 2005], 443). See also, Patrick McNamara and P. Monroe Butler, “The Neuropsychology of Religious Experience,” in Handbook of the Psychology of Religion and Spirituality, 2nd ed., ed. Raymond F. Paloutzian and Crystal L. Park (New York: Guilford Press, 2013), 215-33; and Ralph W. Hood Jr. and Zhuo Chen, “Mystical, Spiritual, and Religious Experiences,” in Handbook of the Psychology of Religion and Spirituality, 2nd ed., ed. Raymond F. Paloutzian and Crystal L. Park (New York: Guilford Press, 2013), 422-40.  Ralph W. Hood Jr. and Jacob A. Belzen, “Research Methods in the Psychology of Religion and Spirituality,” in Handbook of the Psychology of Religion and Spirituality, 2nd ed., ed. Raymond F. Paloutzian and Crystal L. Park (New York: Guilford Press, 2013), 76-77; Hood and Chen, “Mystical, Spiritual, and Religious Experiences,” 429.  Norbert Schwarz and Gerald L. Clore, “Mood, Misattribution, and Judgments of Well-Being: Informative and Directive Functions of Affective States,” Journal of Personality and Social Psychology 45, no. 3 (September 1983): 513-23; “How Do I Feel About It? Informative Functions of Affective States,” in Affect, Cognition, and Social Behavior: New Evidence and Integrative Attempts, ed. Klaus Fiedler and Joseph P. Forgas (Toronto, Canada: C.J. Hogrefe, 1988), 44-62; Clore and Gasper, “Feeling is Believing,” 24-25.  Cf. Simmons and Benson, The New Phenomenology, 23.  Hans-Georg Gadamer explains that all experiences are prejudicial since they are mediated by language, concepts, and cultures (Hans-Georg Gadamer, Truth and Method, 2nd rev. ed., trans. Joel Weinsheimer and Donald G. Marshall [1975; repr., New York: Bloomsbury, 2013], esp. 278-386).  van den Toren, Christian Apologetics, 43.  Paul J. Griffiths, “An Apology for Apologetics,” Faith and Philosophy 5, no. 4 (October 1988): 407.  Cf. Merold Westphal, Transcendence and Self-Transcendence: On God and the Soul (Bloomington, IN: Indiana University Press, 2004), 142-74.  Lewis, Testing Christianity’s Truth Claims, 171.