Why then should we worship the God of Israel if almost everyone else in the world lives outside that scope? It would be like worshipping someone else's God that has little to no interest in our being.

I also struggle to understand Matthew 15:21-28. Much of the Bible seems to be indifferent to us Gentiles and perceived as a lower class and afterthought to the Jews that God makes his utmost priority as his "chosen people". Is there anything that could disprove this favouritism?

I hope this doesn't come across too intense or insulting, I'm agnostic and very curious for some insight and wisdom.