Adventism yana nufin tsarin bangaskiyar addinin Kirista wanda ke jaddada zuwa na biyu ko "zuwan" Yesu Almasihu. Masu Adventists sun gaskanta da dawowar Kristi zuwa duniya da kuma mahimmancin yin shiri don zuwansa ta wurin tsarkin kansa, nazarin Littafi Mai Tsarki, da bishara. Kalmar "Adventist" ta samo asali ne daga kalmar Latin adventus, ma'ana "zuwa" ko " isowa." Adventism ya ƙunshi ƙungiyoyi daban-daban kamar su Adventist Day Adventists, Advent Christian Church, da sauransu.