Exodus 22:20

He that sacrifices unto any god, except unto the LORD only, he shall be utterly destroyed.

Deuteronomy 17:2-5

If there is found among you, within any of thy gates which the LORD thy God gives thee, man or woman that has wrought wickedness in the sight of the LORD thy God in transgressing his covenant

Numbers 25:7-8

And when Phinehas, the son of Eleazar, the son of Aaron the priest, saw it, he rose up from among the congregation and took a javelin in his hand;

Deuteronomy 13:1-15

When there arises among you a prophet, or a dreamer of dreams, and gives thee a sign or a wonder,

Deuteronomy 18:20

But the prophet which shall presume to speak a word in my name which I have not commanded him to speak or that shall speak in the name of other gods, even that prophet shall die.

Numbers 21:3

And the LORD hearkened to the voice of Israel and delivered up the Canaanite; and they utterly destroyed them and their cities, and he called the name of the place Hormah.

Numbers 25:2-4

who called the people unto the sacrifices of their gods; and the people ate and bowed down to their gods.

Joshua 23:15-16

Therefore it shall come to pass that as all the good things are come upon you, which the LORD your God promised you, so shall the LORD bring upon you all the evil things until he has destroyed you from off this good land which the LORD your God has given you

Treasury of Scripture Knowledge

Summary

He that sacrificeth unto any god, save unto the LORD only, he shall be utterly destroyed.

Bible References

Sacrificeth

Numbers 25:2
who called the people unto the sacrifices of their gods; and the people ate and bowed down to their gods.
Deuteronomy 13:1
When there arises among you a prophet, or a dreamer of dreams, and gives thee a sign or a wonder,
Deuteronomy 17:2
If there is found among you, within any of thy gates which the LORD thy God gives thee, man or woman that has wrought wickedness in the sight of the LORD thy God in transgressing his covenant
Deuteronomy 18:20
But the prophet which shall presume to speak a word in my name which I have not commanded him to speak or that shall speak in the name of other gods, even that prophet shall die.

Utterly

Numbers 21:3
And the LORD hearkened to the voice of Israel and delivered up the Canaanite; and they utterly destroyed them and their cities, and he called the name of the place Hormah.
Joshua 23:15
Therefore it shall come to pass that as all the good things are come upon you, which the LORD your God promised you, so shall the LORD bring upon you all the evil things until he has destroyed you from off this good land which the LORD your God has given you