Essential verses to understand this topic
لَـٰكِنِ ٱلَّذِينَ ٱتَّقَوْا۟ رَبَّهُمْ لَهُمْ غُرَفٌ مِّن فَوْقِهَا غُرَفٌ مَّبْنِيَّةٌ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَـٰرُ ۖ وَعْدَ ٱللَّهِ ۖ لَا يُخْلِفُ ٱللَّهُ ٱلْمِيعَادَ
But those who have feared their Lord - for them are chambers, above them chambers built high, beneath which rivers flow. [This is] the promise of Allāh. Allāh does not fail in [His] promise.
إِنَّآ أَرْسَلْنَـٰكَ بِٱلْحَقِّ بَشِيرًا وَنَذِيرًا ۖ وَلَا تُسْـَٔلُ عَنْ أَصْحَـٰبِ ٱلْجَحِيمِ
Indeed, We have sent you, [O Muḥammad], with the truth as a bringer of good tidings and a warner, and you will not be asked about the companions of Hellfire.
وَعَدَ ٱللَّهُ ٱلَّذِينَ ءَامَنُوا۟ مِنكُمْ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ لَيَسْتَخْلِفَنَّهُمْ فِى ٱلْأَرْضِ كَمَا ٱسْتَخْلَفَ ٱلَّذِينَ مِن قَبْلِهِمْ وَلَيُمَكِّنَنَّ لَهُمْ دِينَهُمُ ٱلَّذِى ٱرْتَضَىٰ لَهُمْ وَلَيُبَدِّلَنَّهُم مِّنۢ بَعْدِ خَوْفِهِمْ أَمْنًا ۚ يَعْبُدُونَنِى لَا يُشْرِكُونَ بِى شَيْـًٔا ۚ وَمَن كَفَرَ بَعْدَ ذَٰلِكَ فَأُو۟لَـٰٓئِكَ هُمُ ٱلْفَـٰسِقُونَ
Allāh has promised those who have believed among you and done righteous deeds that He will surely grant them succession [to authority] upon the earth just as He granted it to those before them and that He will surely establish for them [therein] their religion which He has preferred for them and that He will surely substitute for them, after their fear, security, [for] they worship Me, not associating anything with Me. But whoever disbelieves after that - then those are the defiantly disobedient.
Important terms related to this topic
رَبَّنَآ إِنَّكَ جَامِعُ ٱلنَّاسِ لِيَوْمٍ لَّا رَيْبَ فِيهِ ۚ إِنَّ ٱللَّهَ لَا يُخْلِفُ ٱلْمِيعَادَ
“Our Lord, surely You will gather the people for a Day about which there is no doubt. Indeed, Allāh does not fail in His promise."”
Allah keeps His appointments.
وَٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّـٰلِحَـٰتِ سَنُدْخِلُهُمْ جَنَّـٰتٍ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَـٰرُ خَـٰلِدِينَ فِيهَآ أَبَدًا ۖ وَعْدَ ٱللَّهِ حَقًّا ۚ وَمَنْ أَصْدَقُ مِنَ ٱللَّهِ قِيلًا
“But the ones who believe and do righteous deeds - We will admit them to gardens beneath which rivers flow, wherein they will abide forever. [It is] the promise of Allāh, [which is] truth, and who is more truthful than Allāh in statement.”
No one more truthful than Allah.
وَعَدَ ٱللَّهُ ٱلْمُؤْمِنِينَ وَٱلْمُؤْمِنَـٰتِ جَنَّـٰتٍ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَـٰرُ خَـٰلِدِينَ فِيهَا وَمَسَـٰكِنَ طَيِّبَةً فِى جَنَّـٰتِ عَدْنٍ ۚ وَرِضْوَٰنٌ مِّنَ ٱللَّهِ أَكْبَرُ ۚ ذَٰلِكَ هُوَ ٱلْفَوْزُ ٱلْعَظِيمُ
“Allāh has promised the believing men and believing women gardens beneath which rivers flow, wherein they abide eternally, and pleasant dwellings in gardens of perpetual residence; but approval from Allāh is greater. It is that which is the great attainment.”
Paradise promised to believers.
