History itself has been witness to the negative effects of religion. It has been used to control the populace, to extort money from the poor, and has been behind many nefarious activities. Religion has been the cause of wars, persecutions, the suppression of knowledge, with the ultimate goal of ruling with an iron fist. It has buried its claws in politics and legislation particularly in the U.S.
Even in today's world religion continues to hold sway over the politics of this United States to the point where we have the phrase 'In God We Trust' inscribed on our currency, in our court rooms, and at one time not so long ago prayer in school was a requirement. In fact, it has even been said that this nation is a Christian nation and that the writers of the Constitution were themselves Christians although this is not true.
There was also a time not long ago that an atheist was not allowed to testify in court because he could not make the oath to god to tell the truth, and also because it was believed that if he did not believe in god he was himself lacking morals and thus not a trustworthy witness. Religious beliefs force you to suppress your most base instincts as a person to please an invisible being whose own actions based on the scriptures are nothing short of tyrannical.
Almost everything that is prohibited in Christianity is something that most of us love. Premarital sex (fornication) is a sin, adultery (extra marital affairs) is a sin, but this could also be a sin if you have been separated but not legally divorced from a woman/man. Certain sexual acts are prohibited by religious law and are considered deplorable. It's no wonder that priests who must take a vow of celibacy are always being accused of sexual misconduct with children. That is the result of sexual repression which is due to the strict rules that one is forced to adhere to for the sake of religion.