Surprisingly, the term Christian is recorded only three times in the KJV New Testament. It comes from the Greek word Christianos (Strong's Concordance #G5546), which merely means a follower of Christ. It is in c. 41 - 42 A.D., when Paul and Barnabas were in Syrian Antioch teaching and serving the church that the word Christian came into existence.
And when he (Barnabas) had found him (Paul), 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, KJV).
Who created the term Christian to refer to those who believed Jesus of Nazareth was the promised Messiah? It was not the Jews, who generally opposed the gospel message and labeled believers, "the sect of the Nazarenes" (Acts 24:5). Additionally, they would have never used the word "Christ," which has the same meaning as Messiah, to refer to believers in him as they completely rejected his claim of being God's Son.
"There is little doubt that the name Christian originated with the Gentiles (pagans), who began now to see that this new sect was so far distinct from the Jews, that they might naturally receive a new designation. And the form of the word implies that it came from the Romans, not from the Greeks.
"Thus the label "Christian" was the name which naturally found its place in the reproachful language of their enemies" (Life and Epistles of St. Paul, Chapter 4).
The Bible defines a true Christian as someone who has repented of their sins, accepted Jesus as their personal Savior (Acts 2:38) and been baptized (Hebrews 6:1 - 2). After baptism they receive the gift of God's Holy Spirit (Romans 8:9), which gives them the power to develop holy righteous character.
Those who are truly called and chosen by God strive to overcome sin and live his way every day of their lives (1John 2:6). They actively seek to obey him (Matthew 4:4, 7:21), which includes the Ten Commandments both in the letter and in the spirit (1John 5:3, Revelation 12:17, 14:12, 22:14).
Those who are converted also fill their lives with countless acts of selfless service to others (Matthew 25:34 - 40, James 1:27). In fact, their general love of humanity, and especially for those who are of the faith, is evident even to those who are their enemies (John 13:35, 15:10 - 17).
In today's world, anyone can claim to be a Christian or assert Christianity as his or her religion without providing any proof. God, however, is not fooled. The Bible makes it plain that a profession of faith, or even membership in a church, is simply not good enough!
Do you believe that God is one? You do well to believe this. Even the demons believe - and tremble in fear (James 2:19, HBFV).
Even those who say they are a Christian and have God's spirit should be able to back up their words with obedience to His words and with works of service (see James 2:14 - 26).
The one who says, "I know Him," (I have a relationship with God) and does not keep His commandments, IS A LIAR, and the truth is not in him (1John 2:4, HBFV).
And why do you call Me, 'Lord, Lord,' but you do not practice what I say? (Luke 6:46, HBFV, see also Matthew 7:21).
The world is chock full of pretend or "just in case" Christians while those who are truly converted are somewhat rare. It pays to know the difference between the two so that a person is not taken advantage of (2Corinthians 11:26, Galatians 2:4, 2Peter 2:1, 1John 4:1).