Nearby ayahs help place verse 65:12 in sequence and meaning.
أَعَدَّ ٱللَّهُ لَهُمْ عَذَابًا شَدِيدًا ۖ فَٱتَّقُوا۟ ٱللَّهَ يَـٰٓأُو۟لِى ٱلْأَلْبَـٰبِ ٱلَّذِينَ ءَامَنُوا۟ ۚ قَدْ أَنزَلَ ٱللَّهُ إِلَيْكُمْ ذِكْرًا
Allah has prepared for them a severe punishment; so fear Allah, O you of understanding who have believed. Allah has sent down to you the Qur'an.
رَّسُولًا يَتْلُوا۟ عَلَيْكُمْ ءَايَـٰتِ ٱللَّهِ مُبَيِّنَـٰتٍ لِّيُخْرِجَ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ مِنَ ٱلظُّلُمَـٰتِ إِلَى ٱلنُّورِ ۚ وَمَن يُؤْمِنۢ بِٱللَّهِ وَيَعْمَلْ صَـٰلِحًا يُدْخِلْهُ جَنَّـٰتٍ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَـٰرُ خَـٰلِدِينَ فِيهَآ أَبَدًا ۖ قَدْ أَحْسَنَ ٱللَّهُ لَهُۥ رِزْقًا
[He sent] a Messenger [Muhammad] reciting to you the distinct verses of Allah that He may bring out those who believe and do righteous deeds from darknesses into the light. And whoever believes in Allah and does righteousness - He will admit him into gardens beneath which rivers flow to abide therein forever. Allah will have perfected for him a provision.