This is one of the more famous quotes that have emerged from this incredible prize-winning novel. The quote itself is actually slightly ironic, as it refers to the relationship between life and death as if these two nouns were actually people. Life is presented as being a figure of such beauty that death is said to be absolutely smitten and mesmerised with it, and has "fallen in love with it." The relationship between death and life is therefore presented as something that is related to the beauty of life. Death is so enamoured with life that it pursues it, ironically ending the very thing that it is so entranced by.
In terms of how this can be related to everyday life, I suppose there is an implicit challenge in this quote. Life is beautiful, so it is our responsibility to live our lives as if they are beautiful to make them worthy of death's love. Whatever our situation or circumstances, we all, therefore, have a responsibility to live life to the best of our ability and to show it to be the beautiful thing that first seduced death.