The king of Assyria brought people from Babylon, Cuthah, Avva, Hamath, and Sepharvaim, and placed them in the cities of Samaria in place of the people of Israel; they took possession of Samaria, and settled in its cities.
When they first settled there, they did not worship the Lord; therefore the Lord sent lions among them, which killed some of them.
So the king of Assyria was told, "The nations that you have carried away and placed in the cities of Samaria do not know the law of the god of the land; therefore he has sent lions among them; they are killing them, because they do not know the law of the god of the land."
Then the king of Assyria commanded, "Send there one of the priests whom you carried away from there; let him go and live there, and teach them the law of the god of the land."
References for 2 Kings 17:27
So one of the priests whom they had carried away from Samaria came and lived in Bethel; he taught them how they should worship the Lord.
But every nation still made gods of its own and put them in the shrines of the high places that the people of Samaria had made, every nation in the cities in which they lived;
the people of Babylon made Succoth-benoth, the people of Cuth made Nergal, the people of Hamath made Ashima;
the Avvites made Nibhaz and Tartak; the Sepharvites burned their children in the fire to Adrammelech and Anammelech, the gods of Sepharvaim.
They also worshiped the Lord and appointed from among themselves all sorts of people as priests of the high places, who sacrificed for them in the shrines of the high places.
So they worshiped the Lord but also served their own gods, after the manner of the nations from among whom they had been carried away.
To this day they continue to practice their former customs. They do not worship the Lord and they do not follow the statutes or the ordinances or the law or the commandment that the Lord commanded the children of Jacob, whom he named Israel.