The name was given by the Greeks or Romans, probably in reproach, to the followers of Jesus ("little Christs!"). It was first used at Antioch. The names by which the disciples were known among themselves were "brethren," "the faithful," "elect," "saints," & "believers." But as distinguishing them from the multitude without, the name "Christian" came into use, and was universally accepted. This name occurs but three times in the New Testament (Acts 11:26; 26:28; 1 Peter 4:16). via: Calvary Chapel See also: Wikipedia and WikiChristian

It's a simple 4 step process.

Don't have time for 4 steps? Then try ABC. Accept that you have sinned and gone against God's commandments. Believe that Jesus was sent from heaven to earth to died in your place for your sins and was raised from the dead by God. Commit your life to follow Jesus and his teachings.