Lovejoy is sometimes seen with a Catholic Priest's cassock. He is a Man of God and a marriage counselor.
It is revealed that he may be friends with Rabbi Hyman Krustofsky because they do a radio show together about religion called Gabbin' about God. His biggest competitors are the NFL, warm beds on a Sunday morning, and cable.
He describes how he initially came to Springfield an eager, idealistic young man in the seventies, only to become cynical and disillusioned about his flock and ministry, mostly due to Ned Flanders, who constantly pesters him with such non-emergencies as coveting his own wife. Lovejoy would dispatch such concerns with maximum brevity so that he could return to playing with his model trains (his true passion), and in one case, his dessert. He wrote a book called Hell: It's Not Just for Christians Anymore and a pamphlet called Satan's Boners.
Regarding his ministry, he once explained to Marge, "I just stopped caring. Fortunately by that time it was the eighties, and no one noticed." Lovejoy demonstrates a thorough knowledge of the Bible, citing parables such as the "foolish man who built his house on sand" in an attempt to warn Homer against the dangers of founding a self-serving "religion". Homer retorts with a random passage of his own, which Lovejoy cites immediately as having no relevance to the discussion. Homer then tries in vain to cover himself by saying, "Yeah ... think about it!" His hobby is toy trains.
His sermons currently vary between dreary recitations of more opaque parts of the Old Testament, to the occasional "fire and brimstone" scaremongering about Hell — and very little of the love and joy that the Reverend's surname suggests. However, some of the sermons, such as the sin of Gambling, occur on weeks that are highly ironic, such as the fact that Reverend Lovejoy's anti-gambling sermon occurring on a week where Bingo is going to be played on Tuesdays, an implied Gambling convention called Monte Carlo night on Wednesday, and having a retreat at Reno, Las Vegas on Saturday. When congregation members begin to nod off, Lovejoy can awaken them by pressing a button on his lectern resulting in pre-recorded sounds, including an eagle, an ambulance siren, a disco whistle and a blimp attack. He has his pet Old English Sheepdog do his "dirty, sinful business" on Ned Flanders lawn.
He hosts Alcoholics Anonymous meetings at the church. However he himself is secretly an alcoholic (as observed on one of Mr. Burns' surveillance monitors).
His tolerant side is demonstrated when he performs a marriage for Hindus (though he apparently thinks Hinduism is a Christian group), co-hosts a religious radio program with Krusty the Klown's rabbi father and admits evolution may be true. However, despite the fact that he married a Hindu couple, he is unable to identify Apu's religion sometimes. His words of comfort to death-row inmates are "There, there, there, there." and "Well, if that's the worst thing to happen to you today, consider yourself lucky."
However, Lovejoy has become increasingly intolerant, possibly to mirror the increasing extremism of the American Religious Right in recent years. He called Lisa, who had converted to Buddhism, "Marge Simpson's devil-daughter". Moreover, he appears bitter about the tall Episcopal church across the street, wanting to build a larger steeple and, when mentioning the other church, placing the emphasis on "pis". He also read to Lisa an excerpt from the Bible to justify Whacking Day (during which many snakes are killed), but refused to show her the supposed text supporting his argument. While he seems to have originally believed in evolution, he later takes up the creationist cause to bolster his church's membership. He has also driven a "Book-burning-mobile", further revealing an extremist nature. He seems rather stingy as well. In one episode, it is revealed that Lovejoy checks his Bible out of the local library every Friday for 9 years; when the librarian asks him whether it would be easier to simply buy a Bible, Lovejoy acidly implies that it would be possible on a librarian's salary.
He is especially intolerant of the Roman Catholic Church as he is shown brawling with a priest, telling Marge that he might as well do a Voodoo dance for Abe Simpson when he asked him to give him the last rites, and helped kidnap Bart to keep him from converting to Catholicism.
Despite being a clergyman, Lovejoy does not always follow the word of the Bible, and has been shown to do things that would be considered sinful. Lovejoy has been known to exploit his congregation for money, brawl with a Catholic priest, encourage his dog to foul Ned Flanders's lawn, told Moe he had little to live for, and burned down his church for insurance money.
Lovejoy is not always enthusiastic about The Bible and is often disparaging about its content and purpose, ("Have you ever really read this thing? Technically, we're not allowed to go to the bathroom.") this most likely means that he believes it is impossible or very hard to be completely free of sin. He tends to stress church and community work over any involved study of biblical text.
He is proven to be a poor parent; he is usually seen spending more time with his wife and hobbies rather than with his daughter Jessica, who sends her to boarding school for the majority of the time.
Also, he has been known to be somewhat enthusiastic about burnings, as evidenced by the fact that he owns a van that's sole purpose is to burn books (named the burning-book-mobile), which he thanked Lisa personally for writing the article that inspired him  and his declaration that his entire parish, as well as the entire town, try to burn Krusty the Clown products after it was believed that he committed an armed robbery at the Kwik-E-Mart. This trait of his also has passed beyond into his personal behavior; he also had deliberately set his church on fire several times to gain the insurance money covered with it.
It's no secret that he hates Homer. He even wanted Marge to leave him, but Marge refuse to do it. Lovejoy usually tells everyone that Homer is horrible and even wrote "Jesus Died For This!" Picture of Homer sleeping in church.
Reverend Lovejoy's daughter Jessica is normally ignored by her father who refuses to believe she is worse than Bart even after she stole the church's donations.
Lovejoy's wife, Helen, who looks older than her husband, is a moralistic gossip. Now Helen is rarely seen without being at her husband's side. Despite the 1950s aura, it is she, not her husband, who is the driver of the van that takes the Lovejoys out of town when Homer Simpson is deeded the church by the court after suing them for falling in a hole outside the church building and ends up bringing the wrath of God upon Springfield, which is allayed only by the Lovejoys' return.
Most likely prior to meeting Helen, Reverend Lovejoy had a relationship with Edna Krabappel.
Reverend Lovejoy's father has appeared once, in Springfield's burlesque house, La Maison Derrière.
Lovejoy also has a bad relationship with his mother in law. He said that after Helen's father died, she never stopped visiting.