The original title for Dante Alighieri's work was simply "Commedia," or Comedy ("Divina," or Divine, was added later in the 16th C.). In contrast to the other major genres of the period (myth, epic, and tragedy), a comedy moves from discord to merriment. Dante wanted to take the people of his time on a journey from sadness to joy, through Hell and Purgatory to Paradise. He wanted them to see Heaven and God!
The Comedy is also one of the finest works of the imagination. Like Homer's Odyssey, it combines the prevailing worldview of its time with the arts, philosophy, theology, and science. In fact, some call it a work of science-fiction, but I think that sub-classification is limiting. It was written at the end of a bleak time in human history, The Middle Ages, or "The Dark Ages," the period between the fall of the Roman Empire and the Renaissance ("Cultural Rebirth"). Dante's age was cruel and corrupt, but he could sense an a new hope arising from the upheaval of the people of Europe. That new hope was the invention of paper and the printing press and, with them, the flourishing of ideas that would lead to the Renaissance. So, the Comedy is a kind of historical allegory: from darkness will come light. Again, through hell will heaven visible be.
Dante wrote much of the The Inferno and Purgatory while he was on the run, in exile from his native city-state of Florence, which was bitterly divided between two factions. He had to seek asylum in Italian cities in the North, and maybe even France and England. He was vexed at the plight of his city-state, Italy, and the Holy Roman Empire by the time he completed The Inferno by 1312. In the Comedy, he poses a theological challenge to his readers: hell is composed of those who rebel against God's law and mercy. He saw sin on the streets of Florence, in the canals of Italy, and in the offices of the Roman Church. There is no hiding it: the Inferno is a warning to sinners. The people of the Middle Ages believed in a stratified society, "The Great Chain of Being." It is a ladder where God, angels, and demons are at the top and animals, plants, and minerals are on the bottom. Man is on both sides of the division between the upper "Spirit" world and the lower world of "Matter." Sin separated man from God.
Dante also believed in an earth-centric universe. So, his Inferno is a map that shows earth in the middle and hell as a cone-shaped, laddered crater below Jerusalem. So, Dante is saying to the people of his day that the universe is intricately ordered, even mechanized, and that the actions in one's life have infinite consequences in the afterlife. Dante also tells those in the Dark Ages that not only is hell a mirror-image of the Great Chain of Being-- numbered circles of punishment--but the afterlife is itself a journey, every bit the struggle that it is on earth. Dante warns the people of his time that there must be a sense of urgency is this life, for the consequences to come are a reflection of one's moral choices. Dante hoped that the people of the Middle Ages would read his entire work, which included Paradise as well as the Inferno (as many of us do today). The ultimate goal of the entire work is Dante's moving his pilgrim through hell toward God and Heaven. He says, in the end:
In its depths I saw contained, bound with love
in one volume, what is scattered
on leaves throughout the world
Dante is saying that there is both one God-Creator and the many God-in-nature, who orders and sustains life throughout the universe, even down to the plant world. God can be seen through revelation.
Dante breathes beauty across the pages of his poetry. His terza rima ("third rhyme") helps him convey his message. If the medium is the message, then Dante's interlocking rhyming pattern is a metaphor in itself for his people. He says, above all, that the beauty of imagination and language will sustain all people for all times. The Comedy is a beautiful sounding poem, order within order within order. Its echoing of vowel and consonant sounds were made for a people who were largely illiterate so, in the century before the printing press, they could remember his words and repeat them often. In a time-period where only a few works of literature were canonized, Dante's Comedy scattered language like leaves throughout his dark world.
Wow, now that's a broad question jamisonr22, and the answer is not clear cut.
First, it might be helpful to know some of the context Dante was writing. Dante was writing in the 14th Century, a time of great social change in Europe which laid the foundations for what later would become 'The Renaissance' and the shift from what we call "modern" and "medieval" society. In "medieval" society, the catholic church was absolutely integral to all aspects of life. The pope had real political power in almost all European nations, especially the Italian countries of this period, and all the intellectuals of the time where essentially church scholars. Dante is writing against that. Rather than writing in Latin, he wrote in Italian. In doing this, he is basically making a stand for Nationality over the supremacy of the church, and thus wants to write an ITALIAN book free from the influence and authority of the pope.
The book is, however, extremely religious in tone, and here's where the debate lies. It is obviously about Christianity and living a Christian life, yet contains a lot of satirical moments and moment of great imagination and fancy. It can therefore be seen as an extremely pious book, albeit a different kind of religious experience to the authoritative kind of the catholic church. It can also be seen as using that religious structure to get away with quite a few things - along with a few snide jokes at expense of his Italian mates/peers!
The question is really for you to answer in terms of your own relationship to the book, but its a book that's 'about' the relationship between religious life and secular life/ the nation verses the church and individual religious faith versus collective religious experience.