The episode "Hell Is Other Robots" centers around Bender becoming addicted to high-voltage electricity, then discovering the religion of Robotology to help him break the habit. Sermons are conducted at the Temple of Robotology by the Reverend Preacherbot, a character whose mannerisms draw heavily on typical inner-city African-American pastor stereotypes. The name Robotology is a play on the name Scientology, and according to series creator Matt Groening he received a call from the Church of Scientology concerned about the use of a similar name.
Robotology has a holy text, referred to as The Good Book 3.0 and stored on a 3.5" floppy diskette. Two symbols of the religion are shown in the episode. The first is a zig-zag line with a circle at either end, based on the symbol used for resistors on circuit diagrams.
Robots who accept Robotology are expected to abstain from behavior such as smoking, pornography, stealing, abusing electricity, and alcohol. Consuming alcohol is usually necessary to power a robot's fuel cells, but this episode establishes that mineral oil is an acceptable substitute. Sinners are punished by condemnation to Robot Hell, located under an abandoned amusement park in South Jersey. The punishments in Robot Hell are similar to the levels and rationale which are portrayed in Dante's Divine Comedy, specifically the Inferno.
Robot Hell is controlled by the Robot Devil. He is bound by the "Fairness in Hell Act of 2275", allowing anyone who can defeat him in a fiddle contest to go free, as well as win a golden fiddle, a reference to the song The Devil Went Down to Georgia.
The episode "Future Stock" introduces Robot Judaism in a scene where Fry and Dr. Zoidberg, seeking free food, sneak into a "Bot Mitzvah" celebration (a spoof of the Bat Mitzvah). As a joke about Kashrut's proscriptions against shellfish, Zoidberg was not allowed in (despite having Jewish stereotype qualities). At the Bot Mitzvah, Fry asks a Jewish robot if they don't believe in Robot Jesus, to which the robot replies, "We believe he was built, and that he was a very well-programmed robot, but he wasn't our Messiah". A banner written in Hebrew reads "Today you are a robot" (with two misspellings), referencing the traditional Jewish belief that a boy becomes a man on his Bar Mitzvah.
An earlier episode, "Fear of a Bot Planet" also suggested a connection between robots and Judaism, where Bender invents the holiday of "Robannukah" (correlating to Judaism's Hannukah) as an excuse to avoid work, but it is not stated this is actually a Robot Jewish festival.
The First Amalgamated Church is a mix of several mainstream 21st century religions is featured briefly in several episodes. The church and one of its priests, Father Changstein el-Gamal, are introduced in the episode "Godfellas". Father Changstein el-Gamal reappears in "The Sting" at Fry's funeral service, and in Bender's Big Score at Lars and Leela's wedding. In the last of these appearances, the belief system of the First Amalgamated Church is revealed to include agnostic beliefs, the Father beginning the service with the words: "We are gathered here before one or more gods or fewer...".
Passing references are made to other religions, though these are not explored in any detail. In the episode "Hell Is Other Robots", Professor Farnsworth complains about Bender's devotion to Robotology, saying: "If only he had joined a mainstream religion, like Oprahism or Voodoo".
The episode "Where No Fan Has Gone Before" presents the situation of a television show becoming elevated to the status of a religion in the form of the "Church of Trek", where devotees of Star Trek worship the characters and attend services dressed as officers and aliens from the show.
In the second film The Beast with a Billion Backs, Fry becomes the pope of a new religion which worships the interdimensional tentacle monster named Yivo. The church was made out of Yivo's tentacles.
Aside from inventing religions, the writers of Futurama also make references to established faiths.
In the episode "When Aliens Attack", Earth is invaded by Omicronians demanding to see the season finale of Single Female Lawyer, a television show which was accidentally knocked off the air 1,000 years earlier by Fry. Professor Farnsworth explains that the show no longer exists because most video tapes from that era were destroyed during the Second Coming of Jesus in the year 2443. Ken Keeler, the writer of the episode, considered this joke one of the most blasphemous lines in the show, because it suggested that the Second Coming had been and gone and life on Earth had carried on much as before.
Jesus is referenced several times throughout the show, the most notable being on a Tale of Two Santas, where all of the crew dress up as Santa and Zoidberg dresses up as "his friend Jesus" to attempt to stay Bender's execution. When the real Robot Santa appears and attacks the crew and the people attempting to execute Bender, the executioner exclaims "Get him Jesus!" before diving behind an object, and in reference to Benjamin Franklin's famous remark, Zoidberg replies, "I help those who help themselves."
Another undead figure, Chanukah Zombie, first mentioned in the episode "A Tale of Two Santas", makes an appearance in Bender's Big Score. He teams up with Robot Santa and Kwanzaa Bot to fight alien scam artists who have seized possession of planet Earth. His weapons are themed around Jewish symbols and artifacts, including explosive dreidels and a TIE Fighter (a reference to Star Wars; Mark Hamill supplies Chanukah Zombie's voice) adorned with Stars of David and a menorah.
Catholicism is shown to still exist in some form in the 31st century, as the show makes several references to the "Space Pope"; in the opening titles of "Hell is Other Robots" (stating that the show has been "Condemned by the Space Pope"); in "A Bicyclops Built for Two", with Bender's rhetorical question "Is the Space Pope reptilian?"; and in "I Dated a Robot", in an endorsement at the end of an educational film ("Brought to you by the Space Pope"). In the last of these, a graphic displays a picture of the Space Pope as a reptilian alien in Papal vestments, encircled by the words Crocodylus pontifex.
Conversely, Satanism is also shown to still exist in some form in the 31st century. In the episode "A Taste of Freedom," Zoidberg's lawyer, Old Man Waterfall, who is revealed to be a polygamist bisexual libertarian and disabled veteran “of three dozen wars,” requests a Satanic funeral rite before dying.
The episode "Godfellas" explores several religious themes, though without explicitly referencing or parodying any particular religion. Bender is accidentally cast adrift in space and unwittingly becomes a god figure to a race of tiny people (Shrimpkins) living on an asteroid that impacts his body. Bender attempts to answer their prayers, but ends up harming the Shrimpkins. Meanwhile the Shrimpkins who have migrated to Bender's backside, out of his sight, grow frustrated that their prayers go entirely unanswered. Eventually the two factions of Shrimpkins wipe one another out in a miniature nuclear war.
After Bender's unsuccessful attempt at godhood, he encounters a god-like entity in space. During the conversation between them, the episode touches on the ideas of predestination, prayer, and the nature of salvation in what Mark Pinsky referred to as a theological turn to the episode which may cause the viewer to need "to be reminded that this is a cartoon and not a divinity school class". By the end of the conversation, Bender's questions still have not been fully answered, and he is left wanting more from the voice than it has given him. The character/entity has returned, albeit briefly, in the first of the direct-to-DVD installments, Bender's Big Score.
The episode also covers Fry turning to religion to help locate Bender. Seeking guidance, he visits the First Amalgamated Church, which displays a collection of religious symbols above its door, including a Buddha, a cross, a Star of David, a star and crescent and eight multi-colored stars (most likely symbolizing the unity of religions). Later in the episode, Fry visits the "Monastery of Teshuvah" to use the radio telescope of a sect of monks who are attempting to find God in the universe. Teshuvah is the Hebrew word for repentance. The episode also makes reference to The Nine Billion Names of God by Arthur C. Clarke.
The book Toons That Teach, a text used by youth groups to teach teenagers about spirituality, recommends the episode "Godfellas" in a lesson teaching about "Faith, God's Will, [and] Image of God".