Out of one hundred thousand sinners who continue in sin until death, scarcely one will be saved.

Many begin well, but there are few who persevere.

So that you will better appreciate the meaning of Our Lord’s words, and perceive more clearly how few the Elect are, note that Christ did not say that those who walked in the path to Heaven are few in number, but that there were few who found that narrow way. It is as though the Saviour intended to say: The path leading to Heaven is so narrow and so rough, so overgrown, so dark and difficult to discern, that there are many who never find it their whole life long. And those who do find it are constantly exposed to the danger of deviating from it, of mistaking their way, and unwittingly wandering away from it, because it is so irregular and overgrown.

-Saint Jerome, Father and Doctor of the Church