2 Kings 17:33

Yahweh they were fearing, but their gods they were serving, according to the customs of the nations from which they were deported.

1 Kings 18:21

Elijah approached to all the people and said, "How long [will] you [go] limping over two opinions? If Yahweh [is] God, go after him; but if Baal, go after him." But the people did not answer him a word.

2 Kings 17:41

So these nations were fearing Yahweh, but they were serving their idols, as were their children and their children's children; as their ancestors did, they [are] doing until this day.

Matthew 6:24

"No one is able to serve two masters. For either he will hate the one and love the other, or he will be devoted to one and despise the other. You are not able to serve God and money.

Luke 16:13

No domestic slave is able to serve two masters, for either he will hate the one and love the other, or he will be devoted to one and will despise the other. You are not able to serve God and money."

Hosea 10:2

Their heart is false; now they must bear [their] guilt. He himself will break down their altars; he will destroy their stone pillars.

Zephaniah 1:5

and those who bow down on the rooftops to the host of heaven, and those who bow down, swearing to Yahweh but [also] swearing by Milkom,

Treasury of Scripture Knowledge

Summary

They feared the LORD, and served their own gods, after the manner of the nations whom they carried away from thence.

General references

Bible References

They feared

2 Kings 17:41
So these nations were fearing Yahweh, but they were serving their idols, as were their children and their children's children; as their ancestors did, they [are] doing until this day.
1 Kings 18:21
Elijah approached to all the people and said, "How long [will] you [go] limping over two opinions? If Yahweh [is] God, go after him; but if Baal, go after him." But the people did not answer him a word.
Hosea 10:2
Their heart is false; now they must bear [their] guilt. He himself will break down their altars; he will destroy their stone pillars.
Zephaniah 1:5
and those who bow down on the rooftops to the host of heaven, and those who bow down, swearing to Yahweh but [also] swearing by Milkom,
Matthew 6:24
"No one is able to serve two masters. For either he will hate the one and love the other, or he will be devoted to one and despise the other. You are not able to serve God and money.
Luke 16:13
No domestic slave is able to serve two masters, for either he will hate the one and love the other, or he will be devoted to one and will despise the other. You are not able to serve God and money."

General references

Exodus 20:23
You will not make alongside me gods of silver, and gods of gold you will not make for yourselves.
James 1:8
[he is] a double-minded man, unstable in all his ways.