Nietzsche’s dramatic assertion that God is dead is not, as it’s often taken to be, some kind of celebratory statement. Despite his very serious reservations about Christianity, Nietzsche did not think that the end of belief was anything to cheer about. Religious creeds were false, he believed, but he also observed that they were very beneficial in the sense of helping people cope with the problems of life.
Nietzsche felt that the gap left by religion should be filled by Culture (by which he meant the high culture of philosophy, art, music and literature). However, it is worth noting that Nietzsche was also deeply suspicious of the way in which his own era was handling culture. For instance, he believed the universities were (and are) killing the humanities, turning them into dry academic exercises, rather than using them for what they were always meant to be: guides to life, in much the same way religion was meant to be.
He admired the way the ancient Greeks had used tragic drama in a practical, therapeutic way – as an occasion for emotional catharsis and moral education – and wished his own age to be comparably ambitious. He called for a reformation, in which people, newly conscious of the crisis brought on by the end of faith, would fill the gaps left by the disappearance of religion with philosophy and art.