What is a Christian?

Christian

 by Matt Slick
A Christian is someone who follows the teaching of Christianity, a monotheistic, Trinitarian religion which was founded by Jesus of Nazareth 2000 years ago in Israel.  Jesus fulfilled the Old Testament prophecies of the coming Messiah, performed many miracles, and claimed to be divine.  After Jesus' death, resurrection, and ascension, his followers continued the teaching ministry begun by him.
Basically, to be a Christian means to acknowledge who Jesus is, receive the atoning sacrifice, to repent of sin, and to try and live according to what the New Testament teaches.
The term Christian comes from the Greek cristianon (Christianon) and is found in Acts 11:26; 26:28, and 1 Pet. 4:16.  Cristianon is derived from the Greek cristos which means "Christ" or "anointed one" the equivalent of the Hebrew מָשִׁיחַ "Messiah".

• Acts 11:26, "and when he had found him, he brought him to Antioch. And it came about that for an entire year they met with the church, and taught considerable numbers; and the disciples were first called Christians in Antioch."
• Acts 26:28, "And Agrippa replied to Paul, “In a short time you will persuade me to become a Christian.”
• 1 Pet. 4:16, "but if anyone suffers as a Christian, let him not feel ashamed, but in that name let him glorify God."

Within the correct teaching of Christianity is the doctrine of the substitutionary atonement of Christ.  Though there are different theories regarding the atonement, the following verses make it clear that Christ took the place of our punishment due to our sins against God, became sin on our behalf, and bore our sins in his body on the cross.

• Isaiah 53:4-5, "Surely our griefs He Himself bore, and our sorrows He carried; yet we ourselves esteemed Him stricken, smitten of God, and afflicted. 5 But He was pierced through for our transgressions.  He was crushed for our iniquities.  The chastening for our well-being fell upon Him and by His scourging we are healed.
• 2 Cor. 5:21, "He made Him who knew no sin to be sin on our behalf, that we might become the righteousness of God in Him."
• 1 Pet. 2:24, "and He Himself bore our sins in His body on the cross, that we might die to sin and live to righteousness; for by His wounds you were healed."

Not all who claim to be Christian are Christian

Undoubtedly, Jesus was a tremendous figure of ancient times and his deep spiritual teachings found in the New Testament draw millions.  But, just because someone says he or she is a Christian, does not mean he is.
Within Christianity are basic, essential doctrines as defined by the Old and New Testaments.  The Bible teaches monotheism (Exodus 20:3; Isaiah 43:10; 44:6,8); that God is a Trinity (Matt. 3:16-17; 2 Cor. 13:14; Jude 20-21); that Jesus is God in flesh (John 1:1,14; 20:28; Col. 2:9; Titus 2:13; Heb. 1:8); that Jesus rose from the dead physically (1 Cor. 15:14; 17); that salvation is by grace alone through faith (Eph. 2:8-9; Gal. 5:4; Rom. 3:20).  However, there are those who claim to be Christian yet deny one or more of the essentials of the Christian faith.  Such is the case with Mormonism that denies both monotheism and salvation by grace alone.  Jehovah's Witnesses deny Jesus' physical resurrection and salvation by grace alone.  Roman Catholicism denies  salvation by grace alone and adds works of penance, indulgences, and sacraments.  Oneness Pentecostal denies the Trinity.  There are other such groups, but this article is not intended to cover them all.

Christian Statistics

Statistically speaking, Christianity (in the broad sense of the word) is the largest religion in the world with about 2 billion adherents.  Catholicism is the largest group of those who claim to be Christian with Protestants the next largest after that.  Unfortunately, there are more than 30,000 Christian denominations.  If a group holds to the basics of the Christian faith but deviates in non-essentials such as which day to worship on, to baptize by immersion or sprinkling, etc., it is still Christian.  It is the difference in the non-essentials that has lead to so many denominations.  But, denial of an essential means the group is not Christian at its core, even if it claims to be Christian.

Source: http://carm.org/christianity/christian-doctrine/christian