How did the belief in God change from the God of Israel to the God of the whole world?

This is God's grand plan!

Israel is God's chosen people and has been leading them since the Old Testament. In order to strengthen Israel's faith, Moses promulgated the law, and Israel followed God all the way until Jesus Christ became flesh, leaving an eternal gospel.

3 1 year? Jesus was crucified and resurrected three days later, becoming the cornerstone of faith. Christianity was born in Jerusalem under Roman rule.

34 years? Stephen was killed, and the gospel began to spread to the Gentiles and the whole world, becoming the gospel of mankind.

God has also become the god of people all over the world! Jesus Christ has also become the savior of people all over the world!

May I help you, and may God bless you!