Before his ordination to the priesthood he made a retreat at the convent in Vetralla which belonged to the Passionists; it was here that he met the founder St Paul of the Cross. Strambi became impressed and enthralled with what he had seen and admired their ardent devotion. This made him ask the founder to be admitted into the order. But he was refused since Paul of the Cross believed that Strambi did not have the stamina for the Passionist life. Strambi left the convent on 18 December 1767 since he was to be ordained.