Christianity, and all contemporary religion, is a force of great evil. It's not just a tool that is misused, it is fundamentally and at its core, evil. People tiptoe around religion and mollycoddle it because they think to do otherwise is being disrespectful, and because it is so tied to infallible things like "culture" that we can't say anything about it. Plus the religious have this delightful habit of feigning "oppression" whenever somebody dares criticize them.
Anyway to the substance of the point - why is religion, and specifically Christianity, evil?
Reason #1 - The answers it gives to the puzzles of life are deemed infallible without investigation. It does not accept new information and will not correct itself. All new information is retrofitted to fit the narrative already given. Efforts at internal correction are inevitably met with violence because of its deemed "infallibility". The only way religion gets around its litany of obvious errors is to hide behind the poor way in which its commanding documents were written.
#2 - Related to point #1; it is a giant obstruction to enlightenment and greater understanding about the physical world. It has been since time immemorial. All information contrary to the sacred infallible dogma is physically repressed. History is awash with the errors of natural theology. It is also awash with martyrs who unnecessarily had to fight the infallible ones in order to discover the truth. This opposition to understanding continues on to the present day, with Christians everywhere blocking the teaching of Darwinian evolution and attacking Darwinian scientists, to such a point that the subject is barely taught in classrooms today. Meanwhile they conspire to inject junk "science" intelligent design theory, claiming it has equal validity. It is this very phenomenon that inspired the New Atheist movement that inspires so much teeth gnashing about he theistic community. Similarly, they strive to censor literature and art that doesn't conform to their dogma. Look at any story of why this or that book has ever been banned in the United States and inevitably it is because it ran afoul with the holy rollers.
#3 - Not only is it a giant obstruction to understanding the physical world, it is a giant obstruction to social progress. It is a fact that virtually all the churches lined up in support of slavery while it was an issue in American history, while the freethinkers, dissenters, and atheists supported the cause of abolition. The theists can only point to a handful of nominally Christian dissenters as "Christian heroes" who fought for abolition, but one only has to read the speeches of those who fought these battles to know who was on which side. This opposition to progress continues on to the present day. Poll after poll shows that opposition to gay marriage is in direct proportion to religious conviction. Church leaders throughout the country organized constitutional amendment referendums to ban same sex marriage across the country. Christians conspire to help pass draconian legislation in developing countries which make "homosexuality" a capital offense. They make it harder for women to get contraception. They routinely harass and intimidate people for getting check-ups and pap smears at clinics. They take photos of license plates and post people's personal information on websites. They harass relatives of people who go to clinics at their workplaces. This isn't some isolated "Fred Phelps" routine, it is done throughout the country by various church groups. Furthermore, they spread misinformation and lies with their "Crisis Pregnancy Centers", where women are inundated with propaganda and subject to a litany of scare tactics. Organizations like Operation Rescue, which enjoy wide support in the Christian community, have no qualms about terrorizing medical workers who have the courage to help people who need medical treatment. Even to the point of encouraging assassination, as in the case of Dr. Tiller, an event for which they refuse to apologize and take responsibility for. Again, this isn't some isolated act of terror, clinics are being forced to shut down because of these tactics. Some states barely have any functioning clinics, and those they have are under siege. When they're not doing this, they're conspiring to shut down Planned Parenthood, which overwhelmingly serves underprivileged communities with things like cancer screenings. The infallibles do not give a damn about the social cost of their antics. All they care about is being infallible.
#4 - Related to point #3 - Christians hide behind their church walls and preach political messages that they have no business preaching, all while claiming tax exemption status. It is they who are responsible for most of the misinformation and venomous propaganda regarding President Obama that we've had to endure over the past several years. Meanwhile they whine and cry about "persecution" whenever lawmakers have the audacity to say that they cannot impose their views on people just because they monopolize hospitals and other workplaces. Similarly they hide behind their religiosity as they rack up huge profits and pay executives huge bonuses in the healthcare industry, all while claiming to be "non-profits". Nobody knows how much money the Catholic or Mormon Church have because they can't be outdated, but suffice to say Christianity is a big business with long-reaching political tentacles and no accountability whatsoever.
#5 - The scripture from which they take their inspiration, is vile and wicked. It condones slavery, rape, murder, and unimaginable violence. It openly declares that the Messiah was sent to the world to divide families against each other, and to spread violence. It openly declares its intention to conquer the planet for Christianity. This command is made plain by the fact that the earliest Christians sought political power throughout Rome, and waged armed insurrection against Roman authorities. It is also made plain by the fact of the Messiah's crucifixion, a crime reserved for insurrection, and the fact that the Messiah consorted with known terrorists.
#6 - As for the supposed charitable work done by Christian organizations, scratch beneath the surface and it's all a big lie. One of the biggest and widely hailed "saints", Mother Theresa, was very wealthy but invested none of the money in helping the sick, instead focusing on deathbed conversions. She openly consorted with Haitian dictators and S & L scam artists. Much of the missionary "charitable work" is of a similar corrupt character. Billions of dollars are stolen around the world through missionary organizations. Reports by organizations like Transparency International are sober reminders of how replete corruption is in the missionary community. Reports of missionary work in India detail about how poor and sick people are coerced into conversion with promises of 'free of charge' medical treatment, food, or the promise of jobs. The exploitation of the poor and vulnerable by missionaries is truly one of the more despicable crimes of Christianity, and ironically the very one that is used to hail Christianity's supposed virtue.
The fact of the matter is polls show that non-believers are more willing to help others than believers, which speaks to the fraud of the Christian ethos. We'd all be better off, on every imaginable front, without it.