The Bishop's Wife (1947)

Dejected by his efforts to raise money to build a cathedral, Bishop Henry Brougham (David Niven) beseeches heaven for guidance, and is visited immediately by Dudley (Cary Grant), who claims to be an angel. Henry is skeptical, then annoyed when Dudley ingratiates himself into the household as his assistant -- and worse, wins the attentions of Henry's long-suffering and kindly wife (Loretta Young). When Dudley continues to intervene in Henry's struggles, the bishop decides to challenge heaven.