In the Bible there are two basic categories for all of humanity. You have one group, Israel, or the Hebrews, or by Jesus’s day they came to be called “the Jews.” This is the nation of people that God selected among all the nations of the world to be His priestly nation, which would minister to all the other nations of the world.
All the other nations of the world that were not Jews were called “Gentiles.” This is the basic set-up in the Bible. You have Jews and you have Gentiles. And Jesus mission, the reason He took on human flesh, was to come to Israel. His mission was to His people, His priestly nation. All throughout the Gospel of Matthew this was clear. Jesus is preaching to Israel, commanding them to repent. Their nation should have been the one that obedience to God would have been easy. They had every possible advantage, God spoke directly to them. He gave them His Words. He chose to dwell among them on earth in the Temple. They had the most direct access to God out of any people on the planet. Yet they were incredibly wicked people. And Jesus ministry to them was to preach repentance to them. You have sinned grievously and you need to make it right. The signs and the miracles that accompanied His preaching were for the purpose of demonstrating His Word is God’s Word. That’s the entire point of Jesus ministry: Israel’s repentance.