It is wanting to know the end that makes us believe in God, or witchcraft ... to believe, at least in something.
Other Voices, Other Rooms, Truman Capote
When studying history, one will note the Roman Catholic Church has a dark history of being wrong on many issues. Consider their view on Galileo's work or St. Paul advising slaves to be obedient to their masters. Each time science and knowledge has advanced, the Church fought to hang on to ignorance.
Medical science and mental health knowledge have concluded that homosexuality is a normal phenomenon contrary to the Church's 13th century teachings on "natural law." Rather than admit that calling gays "inherently disordered" and worse is simply wrong, an explanation is offered as to why condemning gays is still morally acceptable: the Devil causes a supposed malfunction in fetal development in the womb and so, a gay child is born.
My biggest dissension with Christianity is that it is based on fear. There are liberal clergy preaching a gospel of love; yet to do so, they ignore the bulk of Christian teachings and Christian history. Throughout much of its existence, Christianity focused on fear of the devil and of hell. Even today, the existence of the devil and hell are cardinal doctrinal tenets of almost all Christian creeds. Many fundamentalist preachers still openly resort to terrorizing followers with lurid, sadistic portraits of the suffering of nonbelievers after death.
For over a millennium Christianity arrested the development of science. From the time of Augustine until the Renaissance, systematic investigation of the natural world was restricted to theological investigation and the interpretation of biblical passages. There was no direct observation and interpretation of natural processes because that was considered a useless pursuit, as all knowledge resided in scripture. Scientific knowledge barely advanced in over 1,000 years from the rise of orthodox Christianity in the fourth century to the 1500s.
Not bad enough? Misogyny is fundamental to the writings of Christianity. In passage after passage, women are encouraged, indeed commanded, to accept an inferior role and to be ashamed of themselves for the simple fact that they are women. From the New Testament we find "Wives, submit yourselves unto your own husbands, as unto the Lord. For the husband is the head of the wife, even as Christ is the head of the church ..." (Ephesians 5:22-23) and "These [redeemed] are they which were not defiled with women ..." (Revelation 14:4). From the Old Testament we find "How then can man be justified with God? Or how can he be clean that is born of a woman?" (Job 25:4).
Finally, Christianity from its beginnings has been markedly homophobic. The biblical basis for this homophobia lies in the story of Sodom in Genesis, and in Leviticus. Leviticus 18:22 reads: "Thou shalt not lie with mankind, as with womankind: it is abomination," and Leviticus 20:13 reads: "If a man lie with mankind as he lieth with a woman, both of them have committed an abomination: they shall surely be put to death; their blood shall be upon them." Leviticus declares many other "abominations" and prescribes the death penalty for several other acts. Leviticus 17:10-13 prohibits the eating of blood sausage; Leviticus 11:6-7 prohibits the eating of "unclean" hares and swine; Leviticus 11:10 declares shellfish "abominations"; Leviticus 20:9 prescribes the death penalty for cursing one's father or mother; and Leviticus 20:10 prescribes the death penalty for adultery. Clearly, Leviticus had some issues. Maybe he'd also been "visited" by the Devil in the womb.
Few realize the history of the world is filled with same-gender-loving spirituality. Ancient civilizations, tribes, and sects revered homosexuals as spiritual guardians. As religion became more organized, millions of these shamans, priests, and priestesses were exiled, brutalized, and even killed by the church.
For centuries, in many societies, sex was undifferentiated. Sexual choice was merely a matter of taste. In the Middle East, many non-monotheistic gods and goddesses presented an image of sexual ambivalence and bisexuality. As late as 600 AD, even in Europe, love, friendship, sex, and pleasure were considered interconnected, while marriage was specifically for the purpose of procreation. However, as the church, prejudiced by strict Biblical interpretation, became a monolithic political force in the West, gay people and gay spirituality were brutally denied any contribution to human history, and forced to go underground for hundreds of years. The term "homosexuality" wasn't even coined until late in the 19th Century.
If I were not gay, would I be so wary of Christianity? Indeed. As a thinking being, there are myriad reasons to at least question, if not shun, its teachings.