Warning: Spoilers ahead for "A Wrinkle in Time."

Disney's big-budget adaptation of the best-selling novel "A Wrinkle in Time" falters in many of the same ways the book does — but there was one major change made in the movie from the novel. The film's version of events strips away explicit mention of God or religion, instead trimming down the central conflict to one between "evil" and "light."

Though the film adaptation has several critical flaws — namely pacing and an off-kilter wobble between too much exposition and then not enough — the removal of L'Engle's religious overtones leads to a key issue.

By removing the religious themes, the movie version of "A Wrinkle in Time" loses part of its narrative arc. This leads to a confusing storyline and muddled message when it comes to the antagonist and the purpose of the celestial characters of Mrs. Who, Mrs. Whatsit, and Mrs. Which.

Christianity is integral to the book version of "A Wrinkle in Time"

Author Madeleine L'Engle, who died in 2007 at age 88, spoke about the importance of her own Christian faith as it relates to "A Wrinkle in Time."

"If I've ever written a book that says what I feel about God and the universe, this is it," L'Engle reportedly wrote in her journal. "This is my psalm of praise to life, my stand for life against death."

Calvin (Levi Miller) and Meg (Storm Reid) travel through the galaxy together. Disney

The core story the "A Wrinkle in Time" book is the journey of Meg and Charles Wallace Murray as they try to find and rescue their father. A friend, Calvin, helps them along the way. The trio is guided by three mysterious beings — Mrs. Whatsit, Mrs. Who, and Mrs. Which — to a dark planet called Camazotz where Mr. Murray is being held by an evil force.

The three Mrs. Ws are mysterious beings who materialize in different forms and have different uses of language. At one point, Mrs. Whatsit transforms into "a creature more beautiful than any Meg had even imagined [...] she was a marble white body with powerful flanks, something like a horse but at the same time completely unlike a horse."

Later, the children watch as a star battles the evil shadow — the "Dark Things" which the Mrs. Ws tell the children they need to fight in order to save Mr. Murray. Charles Wallace realizes that Mrs. Whatsit was once a star too, and lost her star-form after battling the Evil.

Mr. Murray (Chris Pine) has been imprisoned by the evil force. Disney

As the Mrs. explain the Dark Thing as an evil "power of darkness," they tell the children that fighters have been battling the Evil in the universe for many thousands of years.

"Jesus! Why of course, Jesus!" Charles Wallace yells when Mrs. Whatsit tells the children they know who the best fighters have been.

Meg and Calvin chime in with other fighters, including Leonardo da Vinci and Gandhi and Buddha.

Later in the book, Meg and Calvin are struggling to explain what the Mrs. beings are. Finally Calvin finds the words, and calls them "angels" and "messengers of God."

As Meg gets closer to facing the evil (also called "IT"), she is told that God has called her to his purpose by both Mr. Murray and the angels.

Mindy Kaling plays Mrs. Who in the movie version of "A Wrinkle in Time." Disney

Before Meg re-enters Camazotz to face IT for the final time, Mrs. Who leaves her with the following quote from Corinthians:

"God is wiser than men; and the weakness of God is stronger than men.

For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called, but God hath chosen the foolish things of the world to confound the wise;

and God hath chosen the weak things of the world to confound the things which are mighty.

And base things of the world, and things which are despised, hath God chosen, yea, and things which are not, to bring to nought things that are."

The movie skips over the religious themes and generalizes "good vs. evil"

Instead of relying on a message from God or using the Mrs. Ws as stand-ins for angels, the movie version of "A Wrinkle in Time" generalizes the idea of evil spreading throughout the galaxy. "IT" is jealousy, fear, and anger, and the Mrs. Ws tell the children that it must be fought by warriors of light and good.

Mrs. Whatsit transforms into what looks like a flying plant-goddess instead of a white horse-like figure, and the topic of stars (or Mrs. Whatsit being a former star) is never invoked. The children also never refer to the Mrs. Ws as angels or messengers of God.

In the movie, Mrs. Whatsit changes into this creature instead. Disney

In the book, Mr. Murray tessers, or sends through time and space, Meg and Calvin away from Camazotz after he realizes IT and the hypnotized Charles Wallace are about to imprison them all. Once they are safely on another planet, Meg confronts her father's cowardice and chooses to go back alone to save Charles Wallace.

In the book, that's when Mrs. Who tells Meg the Corinthians quote about God being wiser than men.

But the movie skips this sequence, instead making it so Meg is simply left behind with Charles Wallace. She comes to realize on her own that loving not only herself but Charles Wallace will bring him back to her. Love in the face of evil is the ultimate weapon.

The story never quite comes together because of the narrative changes

Though Meg's journey to finding self-worth is a valuable narrative, "A Wrinkle in Time" fails to fully explain anything that's going on. Not only is the IT made entirely abstract (whereas in the book IT takes the form a disembodied brain), but the reason the children have to fight IT is also obscured by prose about "being a warrior of light."

And with the removal of the Mrs. being angels or messengers, their role is also muddled. Where did they come from? They simply say they heard a call in the universe, but how? Why? Have they done this before? What is their real form?

These questions are skated over in the books, too, but Calvin's declaration that they are angels brings a much-needed piece of clarity. Without this section in the movie, their presence is compelling but ultimately lacks explanation.

Mrs. Which (Oprah Winfrey) is one of the beings who helps Meg in her journey. Disney

And while Meg's arc in the movie is rightfully highlighted, the entire third act falls apart because it's not made clear what she's fighting.

In the movie, Charles Wallace becomes trapped in IT's control during a confusing sequence on a colorful beach where the children are met by the Man with Red Eyes. But the disembodied brain version of IT is never shown. Instead, the evil version of Charles Wallace becomes the main antagonist for the remainder of the movie, making it both confusing and more creepy than some might be expecting.

Though DuVernay and the screenwriters had no obligation to keep the Christian themes in the movie, the changes that they made seem to have warped the pacing and clarity of the story.

By taking out the religious reasoning behind the Mrs. Ws appearance, and removing the physical manifestation of IT, the movie version of "A Wrinkle in Time" was left incomplete. The biblical inspirations could have (and should have) been replaced with a more cohesive plot that carried the film to its final climax.

As critics continue reacting to "A Wrinkle in Time" with disappointment and confusion, it's not hard to trace the movie's issues back to the narrative shifts made.

To see what major critics are saying about "A Wrinkle in Time," read our roundup of the movie's reviews here.