For the Jewish people, prayer has served as the vehicle by which they have expressed their joys, sorrows and hopes: it has played a major role in the religious life of the Jewish nation, especially in view of the successive crises and calamities in which they have been involved throughout their history. In such situations Jews continually turned to God for assistance. Thus in the Torah the patriarchs frequently addressed God through personal prayer. In addition to personal prayer, Jews have throughout history turned to God through communal worship. In ancient times Jewish communal worship centred on the Temple in Jerusalem. In recent times all groups across the Jewish spectrum have produced new liturgies (such as those that commemorate Holocaust Remembrance Day, Israel Independence Day and Jerusalem Reunification Day). Moreover, a wide range of occasional liturgies exist for camps, youth groups and havurot.