“And when he had found him, he brought him unto Antioch. And it came to pass, that a whole year they assembled themselves with the church, and taught much people. And the disciples were called Christians first in Antioch.” Acts 11:26
The word “Christian” means a follower of Christ. Those in Antioch noticed that these believers followed Christ, therefore they called them Christians. Christianity would be much different if those of this world noticed that Christians were followers of Christ, because it was obvious they did follow Christ, instead of Christians having to try to convince others that they are a follower of Christ.