Psalm 106:35

But they mingled with the [idolatrous] nations
And learned their ways,

Judges 3:5-6

And the Israelites lived among the Canaanites, Hittites, Amorites, Perizzites, Hivites, and Jebusites;

Joshua 15:63

But as for the Jebusites, the inhabitants of Jerusalem, the [tribe of the] sons of Judah were not able to drive them out; so the Jebusites live with the sons of Judah in Jerusalem to this day.

But [the tribe of] Manasseh did not take possession of Beth-shean and its villages, or Taanach and its villages, or the inhabitants of Dor and its villages, or the inhabitants of Ibleam and its villages, or the inhabitants of Megiddo and its villages; so the Canaanites remained in that land.

Judges 2:2-3

and as for you, you shall not make a covenant with the inhabitants of this land; you shall tear down their altars.’ But you have not obeyed Me; what is this that you have done?

Isaiah 2:6

Most certainly [Lord] You have abandoned your people, the house of Jacob,
Because they are filled with influences from the east,
And they are soothsayers [who foretell] like the Philistines;
Also they strike bargains with the children of foreigners (pagans).

1 Corinthians 5:6

Your boasting [over the supposed spirituality of your church] is not good [indeed, it is vulgar and inappropriate]. Do you not know that [just] a little leaven ferments the whole batch [of dough, just as a little sin corrupts a person or an entire church]?