6 These things will be useful to those who already have happily joined the flock of the Lord. But in your midst are those who have not yet been called out of darkness into His marvelous light,(14) who sit in darkness still and in the shadow of death,(15) sheep who now perish, whom you must lead to Jesus, the first pastor of souls. The city of the living God, the Church is bound by no limits and stands open for the salvation of all. Her efficacy has been given her by her divine Founder, and she reaches from sea to sea and daily enlarges the place of her tent and the skins of her tabernacle.(16) Hence by right and merit she is called Catholic. We experience and correctly know that this coming of peoples to Sion the holy mountain is to be attributed to divine grace and that it is God who gives the Christian name its increase. No one can come to me unless the Father draw him.(17) This, however is the plan of the merciful God, proved by the teaching and deeds of our Redeemer, that mortal man cooperates with the work of God for the salvation of souls. For faith, as the Apostle tells us, depends on hearing and hearing on the word of Christ: but how are they to hear if no one preaches? and how are men to preach unless they be sent?(18) Therefore We urge that sacred missions to the Indians be multiplied. May more men of mercy be found who freely and gladly may be sent as workers to the harvest of the Lord. These men do not yield to flesh and blood, but leaving their brothers behind, do everything to win souls for Christ, to bring civilized culture and gentle manners to a barbarous people, and to dispel the darkness of ignorance, so that they may receive a place among those sanctified by faith.(19)
Source: Inter Graves (Vatican.va)