Passage
But if your heart turns away, and you will not hear, but are drawn away, and worship other gods, and serve them;
But if your heart turns away, and you will not hear, but are drawn away, and worship other gods, and serve them;
Deuteronomy 30:15 Behold, I have set before you today life and prosperity, and death and evil.
Deuteronomy 30:16 For I command you today to love Yahweh your God, to walk in his ways, and to keep his commandments, his statutes, and his ordinances, that you may live and multiply, and that Yahweh your God may bless you in the land where you go in to possess it.
Deuteronomy 30:17 But if your heart turns away, and you will not hear, but are drawn away, and worship other gods, and serve them;
Deuteronomy 30:18 I denounce to you today, that you will surely perish. You will not prolong your days in the land where you pass over the Jordan to go in to possess it.
Deuteronomy 30:19 I call heaven and earth to witness against you today, that I have set before you life and death, the blessing and the curse. Therefore choose life, that you may live, you and your descendants;
The verse centers on "heart", "turns", "away", "drawn", "worship", and "other". It is saying that the verse draws attention to "heart" and "turns", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 16's "For I command you today to love..." into verse 18's "I denounce to you today that you...", so "heart" and "turns" belong inside that flow. In Deuteronomy context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "heart" and "turns" with trust shaped by these words, not by a vague optimism outside the passage.