Allah threatens and warns those who revert to disbelief after they believed and who thereafter insist on disbelief until death. He states that in this case, no repentance shall be accepted from them upon their death. Similarly, Allah said,

﴿وَلَيْسَتِ التَّوْبَةُ لِلَّذِينَ يَعْمَلُونَ السَّيِّئَـتِ حَتَّى إِذَا حَضَرَ أَحَدَهُمُ الْمَوْتُ﴾

(And of no effect is the repentance of those who continue to do evil deeds until death faces one of them) ﴿4:18﴾.

This is why Allah said,

﴿لَّن تُقْبَلَ تَوْبَتُهُمْ وَأُوْلَـئِكَ هُمُ الضَّآلُّونَ﴾

(never will their repentance be accepted. And they are those who went astray.) to those who abandon the path of truth for the path of wickedness. Al-Hafiz Abu Bakr Al-Bazzar recorded that Ibn `Abbas said that some people embraced Islam, reverted to disbelief, became Muslims again, then reverted from Islam. They sent their people inquiring about this matter and they asked the Messenger of Allah . On that, this Ayah was revealed,

﴿إِنَّ الَّذِينَ كَفَرُواْ بَعْدَ إِيمَـنِهِمْ ثُمَّ ازْدَادُواْ كُفْرًا لَّن تُقْبَلَ تَوْبَتُهُمْ﴾

(Verily, those who disbelieved after their belief and then went on increasing in their disbelief never will their repentance be accepted). The chain of narration is satisfactory. Thereafter, Allah said,

﴿إِنَّ الَّذِينَ كَفَرُواْ وَمَاتُواْ وَهُمْ كُفَّارٌ فَلَن يُقْبَلَ مِنْ أَحَدِهِم مِّلْءُ الاٌّرْضِ ذَهَبًا وَلَوِ افْتَدَى بِهِ﴾

(Verily, those who disbelieved, and died while they were disbelievers, the (whole) earth full of gold will not be accepted from anyone of them even if they offered it as a ransom.)

Those who die while disbelievers, shall have no good deed ever accepted from them, even if they spent the earth's fill of gold in what was perceived to be an act of obedience. The Prophet was asked about `Abdullah bin Jud`an, who used to be generous to guests, helpful to the indebted and who gave food (to the poor); will all that benefit him The Prophet said,

«لَا، إِنَّهُ لَمْ يَقُلْ يَوْمًا مِنَ الدَّهْرِ: رَبِّ اغْفِر لِي خَطِيئَتِي يَوْمَ الدِّين»

(No, for not even one day during his life did he pronounce, `O my Lord! Forgive my sins on the Day of Judgment.)

Similarly, if the disbeliever gave the earth's full of gold as ransom, it will not be accepted from him. Allah said,

﴿وَلاَ يُقْبَلُ مِنْهَا عَدْلٌ وَلاَ تَنفَعُهَا شَفَـعَةٌ﴾

(...nor shall compensation be accepted from him, nor shall intercession be of use to him,)﴿2:123﴾, and

﴿لاَّ بَيْعٌ فِيهِ وَلاَ خِلَـلٌ﴾

(...on which there will be neither mutual bargaining nor befriending.) ﴿14:31﴾, and,

﴿إِنَّ الَّذِينَ كَفَرُواْ لَوْ أَنَّ لَهُمْ مَّا فِى الاٌّرْضِ جَمِيعاً وَمِثْلَهُ مَعَهُ لِيَفْتَدُواْ بِهِ مِنْ عَذَابِ يَوْمِ الْقِيَـمَةِ مَا تُقُبِّلَ مِنْهُمْ وَلَهُمْ عَذَابٌ أَلِيمٌ ﴾

(Verily, those who disbelieve, if they had all that is in the earth, and as much again therewith to ransom themselves thereby from the torment on the Day of Resurrection, it would never be accepted of them, and theirs would be a painful torment) ﴿5:36﴾.

This is why Allah said here,

﴿إِنَّ الَّذِينَ كَفَرُواْ وَمَاتُواْ وَهُمْ كُفَّارٌ فَلَن يُقْبَلَ مِنْ أَحَدِهِم مِّلْءُ الاٌّرْضِ ذَهَبًا وَلَوِ افْتَدَى بِهِ﴾

,(Verily, those who disbelieved, and died while they were disbelievers, the (whole) earth full of gold will not be accepted from anyone of them if they offered it as a ransom).

The implication of this Ayah is that the disbeliever shall never avoid the torment of Allah, even if he spent the earth's fill of gold, or if he ransoms himself with the earth's fill of gold, - all of its mountains, hills, sand, dust, valleys, forests, land and sea.

Imam Ahmad recorded that Anas said that the Messenger of Allah said,

«يُؤْتَى بِالرَّجُلِ مِنْ أَهْلِ الْجَنَّةِ فَيَقُولُ لَهُ: يَا ابْنَ آدَمَ، كَيْفَ وَجَدْتَ مَنْزِلَكَ؟ فَيَقُولُ: أَيْ رَبِّ خَيْرَ مَنْزِلٍ، فَيَقُولُ: سَلْ وَتَمَنَّ، فَيَقُولُ: مَا أَسْأَلُ وَلَا أَتَمَنَّى إِلَّا أَنْ تَرُدَّنِي إِلَى الدُّنْيَا فَأُقْتَلَ فِي سَبِيلِكَ عَشْرَ مِرَارٍ، لِمَا يَرَى مِنْ فَضْلِ الشَّهَادَةِ، وَيُؤْتَى بِالرَّجُلِ مِنْ أَهْلِ النَّارِ فَيَقُولُ لَهُ: يَا ابْنَ آدَمَ، كَيْفَ وَجَدْتَ مَنْزِلَكَ؟ فَيَقُولُ: يَا رَبِّ شَرَّ مَنْزِلٍ، فَيَقُولُ لَهُ: تَفْتَدِي مِنِّي بِطِلَاعِ الْأَرْضِ ذَهَبًا؟ فَيَقُولُ: أَيْ رَبِّ نَعَمْ، فَيَقُولُ: كَذَبْتَ، قَدْ سَأَلْتُكَ أَقَلَّ مِنْ ذَلِكَ وَأَيْسَرَ فَلَمْ تَفْعَلْ، فَيُرَدُّ إِلَى النَّار»

(A man from among the people of Paradise will be brought and Allah will ask him, "O son of Adam! How did you find your dwelling'' He will say, "O Lord, it is the best dwelling.'' Allah will say, "Ask and wish.'' The man will say, "I only ask and wish that You send me back to the world so that I am killed ten times in Your cause,'' because of the honor of martyrdom he would experience. A man from among the people of the Fire will be brought, and Allah will say to him, "O son of Adam! How do you find your dwelling'' He will say, "It is the worst dwelling, O Lord.'' Allah will ask him, "Would you ransom yourself from Me with the earth's fill of gold'' He will say, "Yes, O Lord.'' Allah will say, "You have lied. I asked you to do what is less and easier than that, but you did not do it,'' and he will be sent back to the Fire.)

This is why Allah said,

﴿أُوْلَـئِكَ لَهُمْ عَذَابٌ أَلِيمٌ وَمَا لَهُمْ مِّن نَّـصِرِينَ﴾

(For them is a painful torment and they will have no helpers.) for they shall not have anyone who will save them from the torment of Allah or rescue them from His painful punishment.

﴿لَن تَنَالُواْ الْبِرَّ حَتَّى تُنفِقُواْ مِمَّا تُحِبُّونَ وَمَا تُنفِقُواْ مِن شَىْءٍ فَإِنَّ اللَّهَ بِهِ عَلِيمٌ ﴾

(92. By no means shall you attain Al-Birr, unless you spend of that which you love; and whatever of good you spend, Allah knows it well.)