Is Christianity an ethnic religion?

It's well-known that in the Bible God mentioned all about Israel and its people like Judaism. Judaism and Christianity believe in the same Bibles also. So Judaism is an ethnic religion according to their claim. If anyone wants to be Jewish, he can't be. One must be from that ethnicity to be Jewish. It's same for many African, Indian, Chinese and so many other ethnic religions. But in case of Islam we see that God never said "O people of Arab". Qur'an is all about people of the world. God always talked about all humankind. So in case of Christianity, it seems an ethnic religion like all other ethnic religions. But why Christians claim it to be universal religion? Did Jesus or God say that the Bible is for all humankind or Christianity is for all humankind? **What is the logic of Christianity being different from other ethnic religions?**