Is Christianity an ethnic religion?

The other answers cover the Biblical aspect well. Here are some numbers. This is the broad distribution of Christianity, according to an article by Pew Research in 2011 ( See https://www.pewresearch.org/religion/2011/12/19/global-christianity-exec/ ):

• The Americas: 36.8%
• Europe: 25.9%
• Sub-saharan Africa: 23.6%
• Asia / Pacific: 13.1%
• Middle-east / North Africa: 0.6%

For a long time, Christianity was predominantly a European religion. That is no longer the case. The trend is expected to continue. As of 2018, Africa was home to 599 million Christians and Latin America to 597 million, meaning that the African continent now has more Christians than any other.

I attend what was once a WASP church in Boston, MA, founded in 1870. Today, the combined number of people attending my church that come from China, Singapore, Nigeria, Zimbabwe, Brazil and other nations equals or exceeds the number of caucasian people.

Revelation 14:6 says it best:

Then I saw another angel flying directly overhead, with an eternal gospel to proclaim to those who dwell on earth, to every nation and tribe and language and people.

Jesus said that if anybody wants to be forgiven and know God and experience His love, there is only one way and that is through believing in Christ Jesus and acknowledging the truth of what he said:

I am the way and the truth and the life. No-one comes to the Father [God] except through me. If you really knew me, you would know my Father as well... Anyone who has seen me has seen the Father. (John 14:6-9)

The truth of this statement is extended to any person, regardless of race, colour, ethnic origin or religion. The free gift of eternal life is open to all who come to saving faith in Christ Jesus.

Furthermore, it does not depend upon works – following rules and regulations. Nobody can earn God’s forgiveness and the salvation that comes through Christ Jesus. Forgiveness is costly to the one doing the forgiving – look at what Christ Jesus had to suffer, laying down his life for sinners such as you and me. Jesus taught that the greatest form of love is self-sacrificial love:

Greater love has no-one than this, that he lay down his life for his friends. You are my friends if you do what I command... I have called you friends, for everything that I learned from my Father I have made known to you. You did not choose me, but I chose you... This is my command: Love each other. (John 15:13-17)

God’s forgiveness is free to the one who is being forgiven. Forgiveness that must be bought, earned or worked for is no forgiveness at all. It requires humility and honesty to face up to the fact that we are all sinners, in need of a saviour. We have to repent, trust and believe in God and what He has done through Christ Jesus. That is the first step. Thereafter, as we learn about God’s love for us by reading His word, the Bible, we find out what it means to follow Christ.

On the night before Jesus was crucified, he prayed to his Father in heaven:

For you granted him [your Son] authority over all people that he might give eternal life to all those you have given him. Now this is eternal life: that they may know you, the only true God, and Jesus Christ, whom you have sent. I have brought you glory on earth by completing the work you gave me to do. And now, Father, glorify me in your presence with the glory I had with you before the world began. (John 17:2-5)

That is why Christianity is unique. Every other religion says you have to work at pleasing God by doing good works (such as praying five times a day and following the other rules in the Qu’ran) in the hope that you might receive mercy. The Bible says God, in Christ Jesus, has done everything that is necessary for us to be adopted into His family. Only believe!

What the Bible says

The portion of the Bible that Christians share with Judaism is the Hebrew Bible (which Christians call the Old Testament), and like you said, the story told there is about God's chosen people, Israel. But the Christian Bible also includes the New Testament which continues the story by including the rest of the world in God's salvation plan for the whole world. This is the Christian principle of progressive revelation. Therefore, like Islam's Qur'an, the Christian Bible is quite explicit that Christianity is most definitely NOT an ethnic religion.

What Jesus said

In both Jewish and Christian interpretation, Israel is a light to the Gentiles, but Christianity extends this further showing that Jesus (a Jew, descended from David) is the embodiment of that light. Jesus's followers, united with Him, are supposed to be the lights to the world as well (cf Jesus's Sermon on the Mount in Matt 5:14-16, c. AD 31), bringing the gospel to everyone (both Jews and Gentiles) so they too can be joined to Christ's body the Church by baptism (cf Jesus's Great Commission in Matt 28:16-20, c. AD 33). It is clear then, that Jesus's express intention was to include everyone.

What God said through the Holy Spirit

The clearest indication of God's intention is recounted in Acts 10 where Peter (the leader of the apostles) received revelation (after Jesus ascended to heaven, c. AD 40) that invitation to belong to God's people includes the "Gentiles" (a.k.a the "nations" which means the rest of the non-Jewish world). Acts 10:34-35:

Peter began to speak: “Now I truly understand that God doesn’t show favoritism, but in every nation the person who fears him and does what is right is acceptable to him.

What Christian theology says

A few decades later, Paul, in his letter to the church in Rome (c. 57 AD), reflected on the relationship of Israel (a nation bound by ethnicity as descended from Abraham), Gentiles (non-Israel nations), and the Church (the body of Christ uniting both Israel and Gentile converts to Christianity). In the language of Paul, Gentiles are engrafted to the olive tree (Israel) thus making Jewish and Gentile converts to Christianity to be reconciled in one body (the Church), no longer enemies but one in Christ, the head of the Church (Romans 9-11).

The seed of his reflection was already evident in his earlier letter to the Galatians church (c. AD 49) where he was emphatic that

There is no Jew or Greek, slave or free, male and female; since you are all one in Christ Jesus. (Gal 3:28, "Greek" is another name for Gentiles)

As you can see from the timeline of the early church, this theology started very early and has remained unchanged in the almost 2,000 year of Christian history (one of the few unanimous teachings of all Christian groups) where (numerically) the Gentiles has surpassed Israel by the end of the first century, making Christianity to be a universal religion de facto as well as by teaching.

What does it mean for us?

Your comments:

Well, Quran claims that Islam is the only religion in sight of God. And God ordered calling "O mankind" a lot of times to believe in him and his prophet Muhammad pbuh. And also warned addressing all humankind not to disbelieve in Him and his prophet. So when God is saying calling humankind, then he is saying to me basically. Also prophet Muhammad confirmed all the prophets came before and claimed as the last prophet. So did Jesus claimed the last prophet? And Matthew 28:20 is only ordering to a group of people. I'm not included into them. So how can you say that it's an order for me?

So can you show any order for all humankind and warning for all humankind. My point is: okay this scripture is from God. But where's the commandments to me? God is basically ordering a group of people. So they are responsible for that order. Why me? And where is the warning or punishment for me if I don’t follow Christianity? In this case God must address all humankind. Not any specific group. Because I'm included in humankind not a particular group like Israelites.

The Christian Bible claims that Jesus is the only way to life (John 14:6), which makes sense because Jesus is not only a prophet, but also God incarnate, which of course Islam doesn't accept. But think about this. If Jesus claimed he can give eternal life to us, he must also be God, because mere human being cannot give eternal life. Becoming a disciple and undergoing baptism is the gateway to have this eternal life given to us after we die. Paul talked about the connection between baptism (which unites us with Jesus) and eternal life at length in Romans 5:12-8:39, esp. Rom 5:21 and Rom 6:4.

You are correct in that Matt 28:18-20 is an order for the 11 apostles (who were already disciples) to "make [new] disciples", i.e. to replicate the good news they had received from Jesus directly to new candidates for disciples, and by baptizing them. After these new candidates were baptized, they in turn can make new disciples of their own. This is how the early church spreads until today, a process called discipleship.

You are also correct that this original group of 11 disciples were all Jewish (which includes Peter), but as Acts 10 showed above, Peter received a command to baptize Gentiles as well. Similarly, Paul, who became a disciple after Jesus revealed Himself to Paul in a special way on the road of Damascus, was specially tasked to make disciples among the Gentiles, thus earning the title apostle to the Gentiles.

I am a Gentile. How can I be a disciple? It's because another Gentile disciple baptized me, making me ALSO a disciple of Jesus. Consequently, when I turned adult, I also need to obey Jesus' command to "make [new] disciples". But I became disciple freely, not under threat of punishment !! Christianity spreads by issuing invitation after explaining the gospel (the good news) that a new disciple has to accept freely. The center of the gospel is the crucified Jesus who is the incarnation of God showing love and mercy to human kind. Can someone who hangs from the cross issue threats? The cross becomes a symbol for Christianity precisely because God humbles himself to us so that we can also humble ourselves. When someone threatens us, we tend to fight back. That's why God the Creator of the Universe adopts this weakest of the weak posture so we lower our guard and lower our pride to receive his gift FREELY, out of thankful recognition that Jesus's suffering on the cross is the consequence of our own sins that He bears for us. That's why my username is GratefulDisciple.

I hope the above explanation helps to show that God from the cross has addressed all mankind, offering salvation. It's up to us whether to receive the gift.

After his resurrection, Jesus commanded his disciples to preach to and convert people throughout the entire world.

18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.

19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:

20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.

-- Matthew 28:18-20

Paul later reiterated this principle, that being non-Jewish did not matter to Christianity:

28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.

-- Galatians 3:28

As did Peter, in Acts chapter 10.