The Romans
فَأَقِمْ وَجْهَكَ لِلدِّينِ ٱلْقَيِّمِ مِن قَبْلِ أَن يَأْتِىَ يَوْمٌ لَّا مَرَدَّ لَهُۥ مِنَ ٱللَّهِ ۖ يَوْمَئِذٍ يَصَّدَّعُونَ
So direct your face toward the correct religion before a Day comes from Allah of which there is no repelling. That Day, they will be divided.
Nearby ayahs help place verse 30:43 in sequence and meaning.
ظَهَرَ ٱلْفَسَادُ فِى ٱلْبَرِّ وَٱلْبَحْرِ بِمَا كَسَبَتْ أَيْدِى ٱلنَّاسِ لِيُذِيقَهُم بَعْضَ ٱلَّذِى عَمِلُوا۟ لَعَلَّهُمْ يَرْجِعُونَ
Corruption has appeared throughout the land and sea by [reason of] what the hands of people have earned so He may let them taste part of [the consequence of] what they have done that perhaps they will return [to righteousness].
قُلْ سِيرُوا۟ فِى ٱلْأَرْضِ فَٱنظُرُوا۟ كَيْفَ كَانَ عَـٰقِبَةُ ٱلَّذِينَ مِن قَبْلُ ۚ كَانَ أَكْثَرُهُم مُّشْرِكِينَ
Say, [O Muhammad], "Travel through the land and observe how was the end of those before. Most of them were associators [of others with Allah].
مَن كَفَرَ فَعَلَيْهِ كُفْرُهُۥ ۖ وَمَنْ عَمِلَ صَـٰلِحًا فَلِأَنفُسِهِمْ يَمْهَدُونَ
Whoever disbelieves - upon him is [the consequence of] his disbelief. And whoever does righteousness - they are for themselves preparing,
لِيَجْزِىَ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ مِن فَضْلِهِۦٓ ۚ إِنَّهُۥ لَا يُحِبُّ ٱلْكَـٰفِرِينَ
That He may reward those who have believed and done righteous deeds out of His bounty. Indeed, He does not like the disbelievers.