Christianity is unique in the way it spread in the face of persecution.
This is obviously untrue. Religious persecution is common, and has been for a very long time. New faiths are often seen as challenges to established power, and clamped down upon forcefully if there are mechanisms in place to do so. Despite this, many survive.
For a contemporary example, look at Falun Gong. The faith is only 18 years old, and for most of that time has been banned by the Chinese government and its practitioners persecuted - many are sent to prison, and key figures are tortured and executed. This has done nothing to halt the spread of the religion - if anything, it has in some ways enhanced its reputation. It has become a symbol for many of opposition to the Chinese Communist Party.
Religions perservering, and even thriving, in the face of persecution is fairly common, so you can't argue this as relevant to the truth of Chirstianity.
What other religion commands that we love our enemies (Matthew 5:43)?
"Revere your enemies as you revere your parents." - Gautama Buddha
That lusting for a woman is adultery (Matthew 5:28)?
Lust is a target for plenty of religions. From the Bhagavad Gita - "It is lust only, Arjuna, which is born of contact with the material mode of passion and later transformed into wrath, and which is the all-devouring sinful enemy of this world."
These are not unique prescriptions of Christianity at all, but even if they were, it's hard to see why having a few unique features makes any religion moe convincing. I'm sure every religion has something unique about it, as could plenty of fictional religions I could make up. This wouldn't make them more likely to be true.