The Three Musketeers is one of my favorite Dumas' novels ....
I have read it and listened to it innumerable times. The Dumas' books in this category are called The D'Artagnan Romances and are comprised of three novels: The Three Musketeers, Twenty Years After and The Vicomte de Bragellone. The last can be subdivided into three novels: The Vicomte de Bragellone, Louis de la Valliere, and The Man in the Iron Mask. The first two books should be read by everyone interested in Dumas. The third part of the last book is also very enjoyable. The first two books of the last are a bit tedious, but should be read if the entire history of the musketeers is to be examined. You must remember that the D'Atagnan Romances were first published in serial form so they can be quite lengthy.
Dumas' was perhaps the greatest writer of dialogue in the 19th century. He combined factual history with fictional characters. Sometimes he makes a mistake, but they are usually small mistakes which do not take anything away from his novels. His novels have a pace seldom experienced in historical literature. Unfortunately, some of his books have been abridged for the youthfull reader. Make certain you do not read one of these.
As for religion, France was nearly all catholic in the times Dumas wrote about. But some of the history he wrote about included the French Huguenots (protestants). In Marguerite de Valois, he covers the Huguenot massacre supposedly started by the Queen Mother, Catherine de Medici. I have never noticed any religous bigotry on Dumas' part.
The Dumas' Romances comprise 48 volumes of fiction interspersed with French history. Reading them all is quite a chore, but the ones I have enjoyed the most are the D'Artagnan Romances and the Marie Antoinette Romances.
Dumas and dostoevsky are in different genres ....
comparing them is unfair. An educated person should read the best of both authors. I would not want to skip the Count of Monte Cristo to read The Brothers Karamazov or vice versa.