103 This peace, which the world cannot give, has been left as a heritage to His disciples by the Divine Redeemer Himself: "Peace I leave with you, my peace I give unto you" ( Saint John xiv. 27); and thus following the sublime teaching of Christ, summed up by Himself in the twofold precept of love of God and of the neighbor, millions of souls have reached, are reaching and shall reach peace. History, wisely called by a great Roman "The Teacher of Life," has proved for close on two thousand years how true is the word of Scripture that he will not have peace who resists God (cf. Job ix. 4). For Christ alone is the "Corner Stone" ( Ephesians ii. 20) on which man and society can find stability and salvation.
Source: Summi Pontificatus (Vatican.va)