39:53
قُلْ يَٰعِبَادِىَ ٱلَّذِينَ أَسْرَفُوا۟ عَلَىٰٓ أَنفُسِهِمْ لَا تَقْنَطُوا۟ مِن رَّحْمَةِ ٱللَّهِ ۚ إِنَّ ٱللَّهَ يَغْفِرُ ٱلذُّنُوبَ جَمِيعًا
“Say, "O My servants who have transgressed against themselves, do not despair of the mercy of Allah. Indeed, Allah forgives all sins."”
Considered by many scholars the most hopeful verse in the Quran. It is an unconditional address to those who have sinned excessively, opening the door of tawbah without condition other than turning to Allah.
39:9
أَمَّنْ هُوَ قَٰنِتٌ ءَانَآءَ ٱلَّيْلِ سَاجِدًا وَقَآئِمًا يَحْذَرُ ٱلْءَاخِرَةَ وَيَرْجُوا۟ رَحْمَةَ رَبِّهِۦ
“Is one who is devoutly obedient during periods of the night, prostrating and standing [in prayer], fearing the Hereafter and hoping for the mercy of his Lord [like one who does not]?”
A rhetorical question contrasting the one who worships sincerely with the heedless, concluding with the famous rhetorical question: "Are those who know equal to those who do not know?"