Passage
But if thy heart turn away, so that thou wilt not hear, but shalt be drawn away, and thou shalt bow down to other gods and serve them;
But if thy heart turn away, so that thou wilt not hear, but shalt be drawn away, and thou shalt bow down to other gods and serve them;
Deuteronomy 30:15 See, I have set before thee this day life and good, and death and evil,
Deuteronomy 30:16 in that I command thee this day to love Jehovah thy God, to walk in his ways, and to keep his commandments and his statutes and his ordinances, that thou mayest live and multiply, and that Jehovah thy God may bless thee in the land whither thou goest to possess it.
Deuteronomy 30:17 But if thy heart turn away, so that thou wilt not hear, but shalt be drawn away, and thou shalt bow down to other gods and serve them;
Deuteronomy 30:18 I denounce unto you this day that ye shall surely perish; ye shall not prolong your days upon the land whereunto thou passest over the Jordan to possess it.
Deuteronomy 30:19 I call heaven and earth to witness this day against you: life and death have I set before you, blessing and cursing: choose then life, that thou mayest live, thou and thy seed,
The verse centers on "heart", "turn", "away", "thou", "wilt", "shalt", and "drawn". It is saying that the verse draws attention to "heart" and "turn", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 16's "in that I command thee this day..." into verse 18's "I denounce unto you this day that...", so "heart" and "turn" 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 "turn" with trust shaped by these words, not by a vague optimism outside the passage.