Not surprisingly, for Karl Barth what it means for a human being to love first comes from what it means for God in Jesus Christ (enfleshed) to love. In Barth’s theology human love is not generated from some sort of deep abyss in the human soul; it is not self generated or directed; it is not correlative to anything in creaturely reality; it is instead, as are all things in Barth’s theology, found in (a doctrine) of God, which conditions his (Barth’s) Christology, and hence, anthropology. Tom Greggs comments on how this is so in Barth’s theology with particular focus on the person and work of the Holy Spirit; he writes:
For Barth, the possibility of the human ability to love is found in Jesus Christ. Yet the actual founding of love in the human is a miracle of the Holy Spirit. Even in this love, there is only ever a correspondence to the love of God in Christ: love begins with God’s unique love for us, and it is only through this that one is able to measure the concept of love. Human loving must, therefore, be understood as an answer to the love of God for us. Under his section ‘The Holy Spirit and Christian Love’, Barth notes:
By the Holy Spirit the individual becomes free for existence in an active relationship with the other in which he is loved and finds that he may love in return. The one who is most deeply filled with the Holy Spirit is the one who is richest in love, and the one who is devoid of love necessarily betrays the fact that he is empty of the Spirit.
Thus, the Spirit provides the condition for the Christian to love, establishing the freedom to know that she is loved by Christ and may love, therefore, in return. Moreover, it is necessary first to know this love, which is revealed, rather than to make Christian love fit a preconceived category of love: true love is known only through the outpouring of the Holy Spirit. Again, one sees here the dual direction of the Spirit’s movement: He establishes the church in the identity of love; but this very identity calls for the other in order to love.
As I recently opined on Facebook: “Loving Jesus is a product of being loved by him first,” which really is just a paraphrase of I John 4.19. But as we consider the implications of what we just read from Greggs things get a little risky! Did you catch what he was developing in regard to Barth’s theology of a Christ concentrated love? Love is not something that humans generate or discover, instead genuine love is a reality that is revealed in the Self-revelation and interpretation of God’s life for us in Christ (see Romans 5.8); a reality that is iterated in our lives as we come to participate in God’s life in union with Christ by the Holy Spirit.
Love in this frame comes directly from God’s life of love. It is a love that is sacrificial and for the other rather than generated from the self; it is ecstatic and for humans it is receptive through participation in God’s mediated life for us in Jesus Christ. This puts a bit of a damper on conceptions of love that are merely portraits of self-actualization at the expense of someone else (i.e. lust). It even puts a damper on religious or “Christian” conceptions of love that overly push certain types of emotional experiences as if that is what love primarily produces. Revealed love terminates in trust, sacrifice, service, and obedience (to God). It compels us to think about the other before ourselves
 Tom Greggs, Barth, Origen, And Universal Salvation (Oxford/NY: Oxford University Press, 2009), 138.