What shall I render to the LORD for all his benefits to me?
I will lift up the cup of salvation and call on the name of the LORD,
I will pay my vows to the LORD in the presence of all his people. Verses 12-14
I'm reading Deuteronomy 13. You know what the Israelites were supposed to do if brother, sister or wife inticed them to go after other "gods?"
"You shall kill them. Your hand shall be first against him to put him to death, and afterward the hand of all the people. You shall stone him to death with stones, because he sought to draw you away from the LORD your God, who brought you out of the land of Egypt, out of the house of slavery." Deuteronomy 13:9-10
This is how serious serving God is. No, we don't stone people to death any more. We don't live in a theocracy, and our local authorities would not look too kindly on us if we killed our relatives because they tried to get us to forsake God.
Still, it is very serious. If someone close to us tries to get us to leave God for a false god, we should at least shun them. Treat them as if they didn't exist. As if we had stoned them to death, perhaps.
The true point of the chapter, however, is not to kill people. It is that we need to be on the alert against false teaching, no matter where it comes from. The person in question might be one of the smoothest orators in the world. He might be extremely popular (more than likely would be), even in the "Christian" realm. But the teaching could be false. We have some very, very popular preachers out there, who are selling books right and left, and people are quoting their stuff. But their teaching is not always true to Biblical principles. We must be careful. We must know the Bible and know when that teaching is false.
Grace and peace, friends