We are suffering the ravages of a society turned in on itself; the “Enlightened,” turn-to-the-subject. This turn knows no boundary between the sacred and secular, it is pervasive among both the elect and reprobate, as it were. Biblically, this turn is the natural condition of humanity, the sin nature is woven deeply into the very fabric of our beings as humans 
in this fallen world. Thus, the organic way to live life is to do so by what Luther identified as the homo incurvatus in se (humanity incurved upon itself). We are oriented by what Augustine identified as concupiscence, or ‘self-love.’ This is the human way, post-lapse, that is to live wayward from the inward of our self-possessed apotheodic lives. On the ‘sacred’ side, whether it be Progressives or Conservatives, we all have this bent, of course, to affirm ourselves, to baptize our ways in the name of Jesus Christ, and indeed, name them, Jesus Christ. We are prone to navel-gaze, and worship ourselves as if we are worshipping the living God; indeed, this is the natural propensity, to look into the words of our lives as if the mirror of God’s Word, rather than allowing God’s Word to be the mirror by which we come to see not our own abstract reflections peering back at us, but instead the communio sanctorum as that is given vivification in the vicarious humanity of Jesus Christ for us, for the world.
Karl Barth takes this type of theme up by referring to the ancient Greek notion of γνῶθι σεαυτόν (‘know thyself’). Here, with his usual thematic candor he recognizes how awry this way of life is if it is thought in abstraction from God’s humanity for us in Jesus Christ. He notes how outrageous it is for humans, in this disposition, to think as if they might have the capacity to construct an ethics for human living and being that in any way elevates itself to the ‘good’ of God’s life. Indeed, as Barth notes, if the self, and knowledge therefrom, is measured by itself, even collectivistically, it might appear as if an abstract humanity has achieved something supererogatory; even as if without God, as God itself. Barth writes:
. . . The right and power and the power with which it tries to assert itself have been borrowed from the very place where theological ethics itself has found the right and power to answer the ethical problem, and will never cease to seek it. In so far as a non-theological ethics has for its content a humanity which is grounded in itself and discovers and proclaims itself, theological ethics will have to deny the character of this humanity as humanity and consequently the character of this ethics as ethics. It will still have to do this even when the latter includes a more or less friendly and appreciative regard for religious and ostensibly even for Christian interests and positions. There is no humanity outside of the humanity of Jesus Christ or the voluntary or involuntary glorifying of the grace of God which has manifested itself in this humanity. There is no realisation of the good which is not identical with the grace of Jesus Christ and its voluntary or involuntary confirmation. For there is no good which is not obedience to God’s command. And there is no obedience to God’s command which is not the obedience of Jesus Christ or His positive or negative glorification. But in its true and strict historical sense γνῶθι σεαυτόν does not lead to the obedience of Jesus Christ and His glorification. In its true and strict historical sense it can be understood only as a summons to rebellion against the grace of God. This rebellion does not become less heinous if later, perhaps, it proceeds to make the grace of God an object of human self-reflection, self-understanding and self-responsibility, to make it a special content of human self-consciousness, and therefore to give to this self-consciousness, among other things, a religious or even a supposedly Christian content, as in the classical attempt of Schleiermacher, the Christian apologist among the Idealists. What begins with the human self cannot end with the knowledge of God and of His command. Nor can it end with the knowledge of the real man and his real situation. In its true and strict historical sense, the γνῶθι σεαυτόν, and an ethics conceived and developed in the practice of this imperative, is shown—post Christum natum [after the birth of Christ]—to be illegitimate and impossible by the death and resurrection of Jesus Christ. In so far as an ethics derives from this source, in so far as it carries out in the background an apotheosis of the self or the self-given answer or the self-undertaken enquiry, in so far as it tries at best (if it does not prefer to be atheistic) to understand God decisively from man instead of man decisively from God, it cannot be regarded by theological ethics as legitimate or possible. Only that well-meaning interpretation in meliorum partem [understood in a charitable sense] can be expected of the latter. It must be content to be understood by it differently (we say better) than it understands itself.[1]
For Barth there is no ‘human self-consciousness,’ no sense of ‘feeling’ or ‘dependence’ on the Divine, as in Schleiermacher, that can ever achieve genuine self-knowledge. If so, the logic follows, that to make an attempt at establishing a system of “right/wrong,” as if a profane ethics might be achieved, Barth rightly shouts a resounding, nein! Instead, in keeping with his usual Christic tenor, Barth only imagines that a genuinely Christian ethics can obtain insofar as that is grounded in the crucified humanity of God in Jesus Christ. As the Son of Man resurrects, this becomes the ‘heavenly soil’ in this far country of a heretofore wayward humanity, wherein a genuine ground and grammar of theological-ethical existence can finally be actualized. Not through a humanity that in ad hoc fashion attaches itself to an exemplarist Christ; not through a human wit that attempts to contact God through tapping into a cosmic Christ-consciousness, as if infused into the human soul; not through an attempt of analogizing from effect to cause, through an interconnected chain-of-being, as if the creation itself has been planted with the vestiges of the Triune logoi waiting to be taken up by a pilgrim’s harvest. No, as Barth rightly understands, any attempt to bridge the infinitely qualitative distance between humanity and God based upon anything other than God freely bridging that distance for us in the humanity of Jesus Christ, becomes an escapade in futility and self-worship; an idolatry of the most heinous specter.
To know thyself, just as for Calvin, as for Barth, apart from God’s Self-knowledge for us in the humanity of Jesus Christ, cannot bring the ‘good’ to humanity. Barth’s thought is shot through with the classical, and dare we way biblical notion that humanity, by itself, is really nothing more than a dissolving shadowy sub-humanity that has no lamp to brighten the path before its sullen and smelly feet. Left to itself this type of humanity can only end up in the dregs of the fiery abyss that originally had been designed for the Devil and his lowly minions. This is the type of antiChrist spirit that an abstract humanity can hope to achieve as far as a theological-ethics; it is an ethics given breath in the reprobate winds of the ‘nothingness’ found in the un-elect of this world order—the realm of the demonic whose telos can only be self-dissolution by God’s judgment.
The world we inhabit, whether the sacred or secular, has imbibed this type of de-cruciformed humanity wherein the only basis of doxology is to sing the pagan chorus of ‘know thyself.’ As Christian people, in particular, in mimicry of their “cultured despisers,” attempt to worship God, from a know thyself mode, they end up, most naturally, singing praises of themselves to themselves, even as if immersed in the Name of the Father, Son, and Holy Spirit. This is the tank of apostasy the world, and Christendom itself, is drowning itself in as it attempts to make a go of it outwith serious submission to the crucified life of God as that has been risen in the humanity of Jesus Christ. Kyrie eleison
[1] Karl Barth, Church Dogmatics II/2 §36 [541-42] The Doctrine of God: Study Edition (London: T&T Clark, 2009), 31-2.