Why are Christians Persecuted?

Why are Christians Persecuted and killed?

“To the angel of the church in Smyrna write: 
These are the words of him who is the First and the Last, who died and came to life again.  
I know your afflictions and your poverty—yet you are rich! I know the slander of those who say they are Jews and are not, but are a synagogue of Satan.  
Do not be afraid of what you are about to suffer. I tell you, the devil will put some of you in prison to test you, and you will suffer persecution for ten days. Be faithful, even to the point of death, and I will give you the crown of life. 
He who has an ear, let him hear what the Spirit says to the churches. He who overcomes will not be hurt at all by the second death.”
Revelations 2:8-11
The above quote is from the book of Revelations. It is talking about the church in Smyrna a city in Asia closely aligned with Rome. A city like Rome very much into emperor worship. A city hostile to Christians.
A famous Christian Martyr Polycarp was the bishop of Smyrna.
The church in Smyrna like many Christians in the world today was under persecution for simply being Christian.
German Chancellor Angela Merkel declared that Christianity is "the most persecuted religion in the world.”
North Korea and Sunni Muslim Saudi Arabia, followed closely by Shia Iran, are among the most oppressive regimes to Christians as well as other religious groups
In Bhutan, where Christians make up 1-2% of its 750,000 population, Christians are not legally recognised at all and cannot have church buildings or cemeteries. Nepal also does not recognise Christianity.
Add to this list communist China, some of the former soviet block countries as well as many other states and terrorist groups such as ISIS.
My question is. Why is Christianity, a religion that preaches peace, love and even obedience to the government that threatening? Could it be that those who oppose Christianity deep down deem it to be true?
C. S. Lewis wrote,
“Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important.”
                                                        C. S. Lewis.
Think about it.