Love, immortality, heart, soul
Love can release, save, redeem and free the soul – give it eternal life, immortality – e.g. the little mermaid or "Alferne paa Heden" ('the faries on the moor'), who may be given eternal life from the love of a human, or, in the case of the fairies, by "a tear of remorse or empathy from the human heart", the angel's love for Inger in "The Girl, Who Trod on the Loaf", Gerda's tears, which thaw Kay's frozen heart in "The Snow Queen" or Sorrow's tear in "The Last Pearl", the pearl that lifts the soul towards the eternal.
According to Flemming Hovmann's commentary p. 95 in vol. 7 of H.C. Andersens eventyr, Dansk Sprog- og Litteraturselskab / Borgen 1990, it is a wellknown motif in popular belief, that tears have such power.
"No," her grandmother answered, "not unless a human being loved you so much that you meant more to him than his father and mother. If his every thought and his whole heart cleaved to you so that he would let a priest join his right hand to yours and would promise to be faithful here and throughout all eternity, then his soul would dwell in your body, and you would share in the happiness of mankind. He would give you a soul and yet keep his own.