"The Lord visited Sarah as He had said, and the Lord did to Sarah as He had promised; Sarah conceived and bore Abraham a son in his old age at the time of which God had spoken to him."
-- Genesis 21:1-2
"For all the promises of God find their 'Yes' in Christ. That is why it is through Him that we utter our Amen to God for His glory."
-- 2 Corinthians 1:20
The story of the Boleyns and their struggle for advancement in English society resembles Abraham's faith-struggle. Both the characters in The Other Boleyn Girl and Abraham compromise themselves morally in favor of seeking after selfish, shortsighted security.
The Other Boleyn Girl demonstrates how the weak morals of a few men can start a rolling snowball of spiritual degradation that ends up crashing down on thousands or even millions of others down the line. A touch of connivery here and a thoughtless lie there builds up enough momentum to rattle Henry Tudor's kingdom and alter the religious/political face of England forever. In a similar way Abraham told a few little fibs here and there in an attempt to make his life easier. His children, in turn, inherited this "little fibbing habit" and expanded it into other areas of their lives. Thus, the entire nation of Israel is plagued from then until now (you can read about in the Old Testament, or the Tanakh).
Out of the entire Boleyn Girl story, Mary's husband (William Carey) is the most despicable moral failure out of all. He possesses a similar moral gutlessness as Abraham, who didn't bother resisting several rulers's invitations to Sarah, for her to join their personal harems. Abraham stood by and allowed these men to take his wife into the bedrooms; Carey practically drove his wife to do the same.
The movie's second biggest moral failure is Mary's father, Sir Thomas Boleyn. He could have put a halt to this sexual debauchery before any it ever got started... instead he saw what he might gain and therefore gave it his blessing. He started off sacrificing his children's happiness to assuage his own financial insecurities. This led to worse things, including the humiliation of the whole family and the public execution of two of his three children.
The Other Boleyn Girl demonstrates the general fact that God appoints husbands to lead their families morally and spiritually, even if they have to die trying. But history tells us that men usually fail morally because they choose selfish gain over doing what is obviously right. As this movie demonstrates, the moral right tends to involve a lot more personal risk. This means that men should lead their households by their faith in God. Taking things into one's own hands requires trust in self; doing the right thing all the time requires trust in God.
Note how the only people to maintain their spiritual bearings in this movie are women. Only Mary, her mother and Katherine of Aragon speak out against their husbands' blatant immorality. They are courageous for begging and pleading with their men, however the fact still remains that God appointed men lead their respective households both morally and spiritually. God decided that men should lead their families into either spiritual prosperity or ruin. Note also how Anne (Natalie Portman) learns to value deception over genuine love thanks to her father and uncle's influence.
The Other Boleyn Girl also demonstrates the general fact that to compromise one's morals is to compromise everything. Almost everyone involved in the events recounted in this movie dies prematurely. Mary, on the other hand, has enough sense to remove herself from the situation, which makes it possible for her to raise her and Anne's children in a healthy environment.
The Other Boleyn Girl stars Natalie Portman as Anne Boleyn, Scarlett Johansson as Mary Boleyn, Eric Bana as Henry Tudor, Jim Sturgess as George Boleyn and Kristin Scott Thomas as Lady Elizabeth Boleyn; based on the novel by Philippa Gregory.