What did the Jews see in the offer of help?

Ezra 4:3 (ESV)

3 But Zerubbabel, Jeshua, and the rest of the heads of fathers’ houses in Israel said to them, “You have nothing to do with us in building a house to our God; but we alone will build to the LORD, the God of Israel, as King Cyrus the king of Persia has commanded us.”

The offer of help may have been voiced in very kind and gentle words, but the people of Israel recognized that it was not a true offer of help. These people wanted to worship the Lord and still carry on worshipping pagan gods as well. If they were allowed to join the Israelites with rebuilding the temple, they would no doubt have also caused them to follow their syncretistic practices.