"how are they to preach unless they are sent?""How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching? And how are they to preach unless they are sent? As it is written, "How beautiful are the feet of those who preach the good news!" (Romans 10: 14-15)
@ SamWiseThat is only because:"...those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified."(Rom 8:29-30)
Exactly. They have to know something theological (they do not teach this anymore The Creed of Saint Athanasius):WHOSOEVER would be saved: needeth before all things to hold fast the Catholic Faith.Which Faith except a man keep whole and undefiled: without doubt he will perish eternally.Now the Catholick Faith is this: that we worship one God in Trinity, and the Trinity in Unity;FURTHERMORE it is necessary to eternal salvation: that he also believe faithfully the Incarnation of our Lord Jesus Christ.Now the right faith is that we believe and confess: that our Lord Jesus Christ, the Son of God, is both God and man.He is God, of the substance of the Father, begotten before the worlds : and he is man, of the substance of his Mother, born in the world;Perfect God : perfect man, of reasoning soul and human flesh subsisting;Equal to the Father as touching his Godhead : less than the Father as touching his manhood.Who although he be God and man : yet he is not two, but is one Christ;One however, not by conversion of Godhead into flesh : but by taking manhood into God;One altogether: not by confusion of substance, but by unity of person. For as reasoning soul and flesh is one man : so God and man is one Christ; Who suffered for our salvation : descended into hell, rose again from the dead;Ascended into heaven, sat down at the right hand of the Father : from whence he shall come to judge the quick and the dead.At whose coming all men must rise again with their bodies : : and hail give account for their own deeds.And they that have done good will go into life eternal : they that have done evil into eternal fire.