Unique but not exclusive
"I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion." Exodus 33.19
According to the pagan mindset, as long as one fulfilled one's ritual obligation to whichever god/ gods one served, one could live as they pleased. This was not how the God of Israel intended it and so He created a nation whose vocation was to be the light of all nations, demonstrating what faithful living should look like. In the days leading up to her destruction by the Assyrians in 722 BC, the northern kingdom of Israel was flourishing, politically and militarily. These were not quite the glory days of David and Solomon but life was good - for those with money and power. In total contrast, Israel's religious life was in a mess.
But God had his man. He was neither a courtier like Isaiah, nor a priest, like Jeremiah. Amos was a shepherd and tended the vines in his sycamore-grove at Tekoa, a small town near Bethlehem and therefore not far from Jerusalem. Amos preached an uncompromising message, pronouncing judgment on the whole nation for the profligate ways of its leaders. This was to be no slap on the wrist but total annihilation, invasion and destruction. There was always the hope of repentance and restoration. God's commitment to Israel is as permanent as his authority over creation is total - even if unacknowledged.
In his sovereign justice God may use one nation to bring judgment on another. Israel was about to learn - the hard way - that its relationship with Almighty God might be unique but it is not exclusive. The same goes for the Church - the New Israel - today...