God "desires all men to be saved and to come to the knowledge of the truth": that is, of Christ Jesus. Christ must be proclaimed to all nations and individuals, so that this revelation may reach to the ends of the earth:

God graciously arranged that the things he had once revealed for the salvation of all peoples should remain in their entirety, throughout the ages, and be transmitted to all generations.

The Catechism of the Catholic Church, page 29.

Photo credit: CNS The popemobile carrying Pope Benedict XVI makes its way through a throng of young people as the pope arrives to celebrate the World Youth Day closing Mass at Cuatro Vientos airfield in Madrid, Spain.