Of Edmund, Robinson Crusoe and Christain morality

"So you are supposed to be a clergyman, Mr Bertram.This is rather a surprise to me."
  "Why should it surprise you? You must suppose me designed for some profession, and might perceive that I am neither a lawyer,nor a soldier, nor a sailor."
 "Very true; in short it didn't occur to me. And you know generally there is an uncle or a grandfather to leave a fortune for the second son."
"A very praiseworthy practice," said Edmund. "but not quite universal. I am one of the exceptions and being one must do something for myself."
"But why are you to be a clergyman. I thought that was always the lot of the youngest where there were many to chose before him."
"Do you think that the church itself is never chosen then?" (Austen: Mansfield Park, Volume 1)

This is the one point in the book where more than ever I felt the idea of the good, virtuous, moral Christian (who happens to be so by choice) seeps through and penetrates the text. We can then safely establish Edmund as the embodiment of this Christian morality. But where does Robinson Crusoe come in all this? It's not just my skewed sense of titles. In other words, a parallel can be drawn between Edmund and Robinson Crusoe and their individual moralities.
Edmund, like Crusoe is "the second son" and so has to "do something" for himself since he isn't the heir to the family fortune. Mary Crawford is surprised by the career that he chooses, namely a willing association with the Church. Edmund, on the other hand argues, Church could be chosen "for itself ", implicitly implying that this is in line with his conscious and willing decision of becoming a clergyman. Ascription to Christian morality then becomes an individual's conscious choice. Crusoe (like Edmund) out of his own decision chooses to repeatedly call on Providence and ascribe to the Christian morality when on the Island.
Not only this but there is also the similarity between these two in the sense that by acting in the capacity of missionaries, they extend the Christian moral code to others as well. While Edmund takes on the responsibility of guiding Fanny in the in ways that she should "show herself a good girl"; Crusoe converts Friday to Christianity. Thereby through Edmund's willful adherence to Christian ideals of morality, Austen puts forth the reader the character of an ideal clergyman. Edmund is not Mr. Collins or Mr. Elton- solely because he chooses not just to preach but also to live by what he preaches.