What is the difference between a Christian and a Gentile?
First, all humans are separated into two groups: Jews and Gentiles. A person is one or the other from birth.
Second, not all Gentiles are Christians. That's where the misunderstanding comes in. There are those who equate Gentile with Christian. They say that if one is not a Jew he is automatically a Christian. Not so.
Third, one is only a Christian by choice of conscience. A Christian is one who decides to follow Jesus and His commandments. Jesus said, "If you love me, keep my commandments."
The proof that one is a Christian is living out the commandments of Jesus. His commandments are summed up in two: love God with all one's being and love one's neighbor as one loves the self.
They say the Christians tortured during the Crusades. No. Gentiles did.
If a person says he's a Christian but does not live the Christian life, then he is a hypocrite. Jesus said that by our fruits we will be known. Look at the fruit on a person's life tree. Is it good or is it bad?
There are those who say that we are not to judge others. That is correct. However, Jesus did tell His disciples to analyze the fruit on another's tree to see if it is good or bad. If it is good according to Jesus' commandments, then that person is judged to be a Christian. If it is bad according to Jesus' expectations, then that person is judged to be a non-Christian.
I often get notes from persons telling me that I am judging others. These notes come when I write about sinners and sin. Then the supposed righteous note me that I am not to judge, as God has stated in the Bible. I then point out to them that I am not judging a soul to heaven or hell. Only God can do that. I am analyzing a life tree and discerning it to be good or bad. There is a huge difference between judging a soul to eternity and analyzing a life tree.
God gives Christians the right to discern others. For instance, the Apostle Paul carried out that responsibility in his letters to the churches.
Therefore, a Christian is one who lives out the commandments of Jesus, that is, he tries with all his being to be like Jesus in every way.
Not all Gentiles make that choice. Therefore, they are Gentiles but not Christians.
Fourth, there are Gentiles who are not Christians who pose as Christians. For instance, during the Crusades there were scores of church people under the power of the church who called themselves "Christians" but they were not. They were merely church people who delighted in their power over others.
In fact, these humans when hurting others were of Satan while calling themselves Christians. They were Gentiles calling themselves "Christians." They were frauds. They were hypocrites.
True Christians would not have acted out what the killers and torturers did during the Crusades.
It is the same in other various periods of Church History. There were those Gentiles in the name of "Christian" who burnt humans at the stake and provided other forms of persecution. These were Satanists and not Christians, though they claimed to be the latter.
Summation: A Christian may be Jew or Gentile. It does not matter in that regard. A Christian-Jew or Gentiles-is one who keeps Jesus' commandments - period. (Jewish Christians are often referred to as "Messianic Jews" or "Jews for Jesus.")