In the last days (ie, during the Tribulation) the persecution of Christians will reach an epidemic level.  There are some early signs of this happening right now today in our world, occurring in fits and starts, but nothing sustained and lasting.  When this begins in earnest it will be like someone poured a tanker full of gas on top of a pile of rocket fuel and threw a match at it.  Again, we are presently in the infant stages of this, but the full scale persecution of Christians as described in this verse won't come into its own until the Tribulation.  Right now we're only in the early "Birth Pangs" part of it.

EDIT (2019-11-1): I know this prophecy is still considered as "In Progress", and will remain so until the 2nd coming of Christ.  However, I don't think that precludes this from being marked as "fulfilled" as we've gone far enough in the fulfillment of this prophecy, in my humble opinion, to classify it as fulfilled.  Not completed, as that comes later.  But rather merely fulfilled.