Of course, if one's reading Kierkegaard for personal interest that's fine - but it's sloppy scholarship just to cherry pick what suits one from a particular author, whether it's Kierkegaard, Heidegger, or whoever. Nevertheless, it does seem to me that even the more religious parts of the authorship can offer significant insights into the meaning of the human condition to those who can't then say that, e.g., they believe Jesus Christ is the Son of God and their personal Saviour.