By Laura Ieraci Catholic News Service VATICAN CITY (CNS) -- Clerics who work in the Vatican's diplomatic corps are not called to be "senior officials of a state" or "a self-preserving superior caste, welcome in worldly living rooms," Pope Francis said. Rather, they must be "authentic pastors," with the "courage to plow" with their own hands the fields of mission to which they are assigned, he told future Vatican diplomats during an audience at the Vatican June 25. The pope met with the current class and staff of the Pontifical Ecclesiastical Academy, which provides training to priests for eventual service in the Vatican's diplomatic corps. The pope said their formation was aimed at making them men who build "bridges" and urged them to guard against attitudes of superiority. Speaking to the future diplomats about their role as representatives of the Holy See, he laid out clearly the charitable mission of the church. "The Holy See is the see of the bishop of Rome, the church that presides in charity that does not rest on vain pride but on the daily courage of compliance -- or rather abasement -- of its master," he said. "The true authority of the church of Rome is the charity of Christ. This is the only power that renders it universal and credible for people and the world," he continued. "This is the heart of its truth, which does not build walls of division and exclusion but is a bridge that builds communion and calls to the unity of the human race." Using vivid farming and fishing metaphors, the pope told them "not to expect the ground ready" when they get to their country of assignment but to "have the courage to plow it with your hands, without tractors or other more effective means," preparing it for sowing and then waiting, with the patience of God, for the harvest," which they may not necessarily benefit from in the future. He also told them "not to fish in aquariums or fish farms but to have the courage to move away from the margins of safety" of what they know, to throw their "nets and fishing rods in less predictable" waters, and not to "get used to eating pre-packaged fish." The pope said their future service includes "protecting the freedom" of the Holy See. In order "not to betray its mission before God and the true good of all people," the pope said, it cannot be "imprisoned by the logic of networks," "be a hostage to cliques," subject itself to "political powers," or be "colonized by the thinking of the day or the illusory hegemony of the mainstream." Vatican diplomats are called to seek the good in the churches and populations in which they serve, the pope said. To achieve this with good results, they must "set aside the attitude of a judge" and take on the role of a teacher, who can draw out the good in the local church and people. He noted the various needs of the different continents and urged the priests not to be discouraged by the hardships they will face in their service.