The antichrist spirit that denies that Jesus came in the flesh two thousand years ago is the same spirit of unbelief that denies that He will literally come again in the flesh.
There are many both in and out side the Church who deny the doctrine of the literal return of Jesus Christ. Some want to 'spiritualize' the prophecies or interpret them a just stories or fables.
They often ridicule those who believe that there are still prophecies to be fulfilled as literally as those fulfilled in the past.