To him Cardinal Stella owes the academic formation that led him to hold prominent posts in Vatican diplomacy, from the Central African Republic to Chad, from Congo to Columbia, with seven years of laborious commitment as apostolic nuncio to Cuba. Former President of the Ecclesiastic Pontifical Academy, Cardinal Stella was nominated Prefect of the Congregation for the Clergy by Pope Francis.
È a lui che il cardinale Stella deve la formazione accademica che lo ha portato a ricoprire ruoli di grande rilievo nella diplomazia vaticana, dalla Repubblica Centrafricana al Ciad, dal Congo alla Colombia.