Ezra - Chapter 4

As soon as the work began on the restoration of the Temple, some Samaritans came to undermine the work, pretending that they wanted to help:

"When the enemies of Judah and Benjamin heard that the exiles were building a temple for the Lord, the God of Israel, they came to Zerubbabel and to the heads of the families and said, “Let us help you build because, like you, we seek your God and have been sacrificing to him since the time of Esarhaddon king of Assyria, who brought us here.”"

Satan's plan to disrupt God's plans from within his people is seen in the same way in Revelation 3, in Jesus' letter to the church at Philadelphia.  Jesus writes to those who are working within the church to oppose it:

"I will make those who are of the synagogue of Satan, who claim to be Jews though they are not, but are liars—I will make them come and fall down at your feet and acknowledge that I have loved you."