The fourth series of Downton Abbey premiered last night in the United States, so my family watched the DVDs of the first three series to refresh our memories and really, for enjoyment. I'll say this is a sort-of spoiler: if you haven't watched, you can stop reading, but it has been out for a while now so I don't feel guilty. ;)
The youngest daughter of the house, Lady Sybil, is quite independent and determined, participating in the women's suffrage movement and serving as a nurse in the Royal Army Medical Corps during the Great War. By the armistice, she realized that she did not desire to return to the fancy parties of la belle Époque. So she marries the family chauffeur, the Irish nationalist Tom Branson and has left for Ireland, only returning because he's on the run from the law while she is with child. Now I've caught you up to the real point of the story.
Sybil showed signs of ecclampsia during the delivery according to the village doctor Dr. Clarkson, who is overruled by the knighted and wealthy obstetrician hired by Lord Grantham, Sybil's father and master of Downton, under pressure from Lord Grantham. Indeed, Dr. Clarkson was right, and Sybil dies. At least in 1920 there was no way to save the mother unless a C-section was performed (even then it was risky and as is revealed later, only a small chance of the mother's survival existed). The decision was made on the certainty of modern scientific evidence, and you really need to watch the show, for Lord Grantham is horrified to find out that modern science is incapable of certainty. It looks for repeatability in the same situation and by doing so it actually escapes finding the truth.
The Great War's disaster and tragedy on an immeasurable scale led to the downfall of the optimism and belief in progress held during the pre-war years. Things became quite unstable as nuclear and quantum physics shattered previous understandings of the universe as a stable, eternal entity (leading it closer to Catholicism actually, and indeed physics can provide useful metaphors for faith!). History is uncertain too, since it is mainly the creation of causal linkages based on interpretations of events with only a selection of the facts, based on imperfect memories and the biases of the selectors. So really this problem of belief is really one for the modern age.
But there have always been issues of belief. Why? No one can see that Our Lord Jesus Christ is fully God and fully man. Divinity and the soul are both invisible entities, thus they have no material form. He is God made visible, but one only knows this through divine assistance, and for us moderns divine revelation presented through catechesis.
The shepherds were told that He was Christ the Lord, the Savior who had been born in Bethlehem. The Magi were given a sign that the Christ Child had been born, and John the Baptist was clearly given this knowledge in the womb, where he received sanctification. He declares, "Behold the Lamb of God. Behold he who takes away the sins of the world." Thus Christ is God, since He is the one who takes away sin, i.e. the Savior. I'm an intellectually-oriented person, and I sometimes need 2+2 to be added to 4, so I'm not even sure it was that hard and that the logical conclusions were even necessary to spell out. After all, the shepherds were eager with their awe and reverence to adore the Infant, the Magi found the Infant without hesitating, and people began to follow Christ at the time of his baptism. They didn't need to be told twice, an example we need to bear in mind daily. The Epiphany and Baptism are both showings of God, by the way, if one breaks down the Greek words Epiphany and Theophany.
Simon Peter confesses that Jesus is the Christ, the Son of the living God, and Our Lord, because faith comes from what is heard (Hebrews 11), states that "flesh and blood hath not revealed it to thee, but my Father who art in Heaven." Thomas's story of doubt provides an interesting example. He does not believe that Jesus is actually present in his bodily form and appearance. There is no way for him to feel or see that Jesus is God, having already heard it and so Thomas declares, once he feels the wounds of Our Lord, "My Lord and my God." For us, no test can prove that Our Lord is present body and blood, soul and divinity in the sacramental mode of bread and wine.
The difference between science and the Catholic faith is this: God provides us with certainty in the midst of uncertainty. All these paradoxes of things that are equally true start to make everything look shaky, yet they are founded on the Logos, upon Truth and Love in the form of a person, Jesus Christ.
Just read Introduction to Christianity by Ratzinger.