1 John 2:2 He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world.
John was a Jew and he learned from Christ that this atonement of sin was not just something to do with the Jews but to do with the whole world!
God created the whole world but worked with the Jews so that we would have our example to look to and learn from.
I sometimes count myself to be very lucky that I am a gentile and that I have come to learn about God through love and support and not through religion.