Karl Barth, hearkens back to John Calvin in many ways; but of course Barth doesn’t do so uncritically, or in ways that remain abstract from Barth’s own theological categories and emphases, formed as they are by his centraldogma of election in God’s life for us, with us, and thus not without us.
So in true to expected form, when discussing salvation and personal knowledge of God, Barth sounds a lot like Calvin, when it comes to Calvin’s basic understanding about knowledge of God and knowledge of self that is then oriented by the proper order of knowing God first. Calvin famously writes in his Institute:
Again, it is certain that man never achieves a clear knowledge of himself unless he first looked upon God’s face, and then descends from contemplating him to scrutinize himself. For we always seem to ourselves righteous and upright and wise and holy–this pride is innate in all of us–unless by clear proofs we stand convinced of our own unrighteousness, foulness, folly, and impurity….
Barth follows this theme in Calvin, but radicalizes it; again, based upon his reified understanding of election and how that implicates both God and humanity in Christ and his unio personalis. In other words, Barth has a thick, robust, and even more explicit and non-dualist theological-anthropology at play when he considers knowledge of God, and knowledge of self. Humanity is objectified, by the subjective humanity of Christ for all; as such, if we really really are serious about understanding ourselves, understanding what it means to be human, what it means to be in relation to God (which is to be rightly human as sustained by the indestructible life of the Son for us) we will always look to complete and all sufficient life of Christ. We won’t engage in the pietist turn of constant self-examination; we won’t psychologize ourselves to death; we won’t be obsessed with an individualist style of Christianity; we will, instead, look out and up toward Christ. This approach definitely changes how we think of our daily walks and spirituality (I will have to comment on how I think that looks later). Here is the way Karl Barth, according to George Hunsinger, understood this kind of Calvinian approach to things:
Therefore, if we sinful human beings are to find the truth of our existence, the reality of our salvation, and the ground of our selfhood before God, the basic rule is that we should look away from ourselves to Jesus Christ. “The greater the concentration with which we look at him, the better will be the knowledge that we have of ourselves” (IV/2, 269). We are not to seek knowledge of our salvation by means of introspection or self-examination. We are to look away from ourselves as consistently as possible. “It is a matter of knowing ourselves . . . in Christ,” writes Barth, “and therefore not here in ourselves, but there outside ourselves in this Other who is not identical with me, and with whom I am not, and do not become, identical, but in whose humanity God himself becomes and is and always will be another, a concrete antithesis” (IV/2, 283). Our self-knowledge as the knowledge of who we are in Christ (who stands over against us even in uniting with us) can only occur as we learn to recognize ourselves in him, since “in truth” we are not outside but are so within him that he is our “truest life” (IV/3, 545).
How badly need this kind of outlook is, in North American evangelicalism in particular. We currently are living in the contemporization and repristination of our Puritan pietist past that emphasizes a spirituality with an undo specter of exhorting Christian people to look inward, to the fruits of their labor, and contrition of their souls to prove to themselves, the church, and the world that they are indeed Christians. And so a Barthian/Calvinian antidote to this kind of (The Gospel Coalition and likeminded movements among evangelicals) ‘spirituality’ as sorely needed. If Jesus is the ground, if he is THE human, and you derive your existence, your human being by participation with and from his by the miraculous re-creative activity of the Holy Spirit; then looking away and to Christ ought to become the balm to the overly burdened and individualized soul who wanes under the weight of its own laborious proof of life.
 John Calvin, Institute, 1.2.37.
 George Hunsinger, How To Read Karl Barth: The Shape of His Theology (New York/Oxford: Oxford University Press, 1991), 119, Nook.