Last year, the British Foreign Secretary Jeremy Hunt ordered a review of religious persecutions.
The preliminary report comes less than two weeks after bombings at three churches in Sri Lanka on Easter Sunday that killed more than 250 people and more than 500 hurt.
The report estimates one in three people suffer from religious persecution—with Christians being the most persecuted religious group.
Typically Jews have been the target, but it was found Christians are being wiped out from parts of the Middle East.
Houston Baptist University assistant professor Dr. Shannon Holzer said persecution doesn't just mean murder, there's a wide spectrum.
"It goes from the outright killing all the way down to just public ridicule, not being able to get a job, the shunning of one by his parents," said Holzer.
He said Christian women are more vulnerable and can be raped, sold into prostitution, sex slave industry, parents are separated from children.
Holzer said there's different religious (Islam and Hindus) and non-religious groups (American atheists) going after Christians, as well as tolerant and non-tolerant countries (like Cuba, China and North Korea).
"Then you have different religious groups doing it all the way to the least religious groups doing it. And, then we have what we would think to be the least tolerant nations doing it to America who we would assume to be the most tolerant nation," said Holzer.
He added Jewish and Christianity are the only faiths that forbids genocide, whereas it's part of the doctrine of other world views.
He said Christians tend to be targeted as they are more outspoken and evangelical and people don't like others sharing their faith.
The review is due to publish its final findings in the summer.