If someone does not believe in the Last Day, no faith or righteous deeds will benefit him at all

Praise
be to Allah

Belief in the
Last Day, and what is connected to it of belief in Paradise and Hell, is one
of the six pillars of faith. Whoever does not believe in any of these six
pillars is a disbeliever in Allah and will abide forever in Hell; no
righteous deeds will benefit him and on the Day of Resurrection no
intercessor will be able to help him.

Allah, may He be
exalted, says (interpretation of the meaning):

“The Messenger
has believed in what was revealed to him from his Lord, and [so have] the
believers. All of them have believed in Allah and His angels and His books
and His messengers, [saying], ‘We make no distinction between any of His
messengers.’ And they say, ‘We hear and we obey. [We seek] Your forgiveness,
our Lord, and to You is the [final] destination’”

[al-Baqarah
2:285].

 And Allah, may
He be exalted, says describing the believers (interpretation of the
meaning):

“… and of the
Hereafter they are certain [in faith]”

[an-Naml 27:3].

It was narrated
from Abu Hurayrah (may Allah be pleased with him) that one day the Messenger
of Allah (blessings and peace of Allah be upon him) appeared before the
people and there came to him a man who said: O Messenger of Allah, what is
faith? He said: “Faith is to believe in Allah, His angels, His Books, His
Messengers, and the meeting with Him, and to believe in the resurrection
hereafter.”  Narrated by al-Bukhaari (4777) and Muslim (9).

According to the
famous hadith of Jibreel, which was narrated by Muslim (8), [Jibreel] said:
Tell me about faith (eemaan). He said: “It is to believe in Allah,
His angels, His Books, His Messengers, the Last Day, and to believe in al-qadar
(the divine will and decree), both good and bad.” He said: You have spoken
the truth.

Belief in the
Last Day is part of belief in Allah; so whoever does not believe in the Last
Day is not a believer in Allah. Allah, may He be exalted, says
(interpretation of the meaning):

“…
but
[true] righteousness is [in] one who believes in Allah , the Last Day, the
angels, the Book, and the prophets…
”

[al-Baqarah
2:177]

“And
[also] those who spend of their wealth to be seen by the people and believe
not in Allah nor in the Last Day. And he to whom Satan is a companion – then
evil is he as a companion”

[an-Nisa’ 4:38]

“Fight
those who do not believe in Allah or in the Last Day and who do not consider
unlawful what Allah and His Messenger have made unlawful and who do not
adopt the religion of truth from those who were given the Scripture –
[fight] until they give the jizyah willingly while they are humbled”

[at-Tawbah 9:29].

And Allah, may
He be exalted, says (interpretation of the meaning):

“Those will have
lost who deny the meeting with Allah , until when the Hour [of resurrection]
comes upon them unexpectedly, they will say, ‘Oh, [how great is] our regret
over what we neglected concerning it,’ while they bear their burdens on
their backs. Unquestionably, evil is that which they bear”

[al-An‘aam 6:31]

“… while they
were, concerning the Hereafter, disbelievers”

[al-A‘raaf 7:45]

“Who took their
religion as distraction and amusement and whom the worldly life deluded.” So
today We will forget them just as they forgot the meeting of this Day of
theirs and for having rejected Our verses”

[al-A‘raaf 7:51]

“Those who
disbelieve have claimed that they will never be resurrected. Say, “Yes, by
my Lord, you will surely be resurrected; then you will surely be informed of
what you did”

[at-Taghaabun
64:7]

“Every soul, for
what it has earned, will be retained

Except the
companions of the right,

[Who will be] in
gardens, questioning each other

About the
criminals,

[And asking
them], ‘What put you into Saqar?’

They will say,
‘We were not of those who prayed,

Nor did we used
to feed the poor.

And we used to
enter into vain discourse with those who engaged [in it],

And we used to
deny the Day of Recompense

Until there came
to us the certainty’”

[al-Muddaththir
74:38-47].

And there are
many similar verses and hadiths.

Muslim (214)
narrated from ‘Aa’ishah [that said said:] I said: O Messenger of Allah,
during the Jaahiliyyah Ibn Jud‘aan used to uphold the ties of kinship and
feed the poor. Will that benefit him at all? He said: “It will not benefit
him, because he did not say one day, ‘Lord forgive me my sins on the Day of
Judgement.’”

An-Nawawi (may
Allah have mercy on him) said:

What this hadith
means is that what he used to do of upholding ties of kinship, feeding the
poor and other noble traits will not benefit him in the hereafter, because
he was a disbeliever. This is what is meant by the words of the Prophet
(blessings and peace of Allah be upon him) “because he did not say one day,
‘Lord forgive me my sins on the Day of Judgement’”, i.e., he did not believe
in the resurrection, and whoever does not believe in it is a disbeliever,
whose good deeds will not benefit him.

Al-Qaadi ‘Iyaad
(may Allah have mercy on him) said: There is scholarly consensus that the
disbelievers’ good deeds will not benefit them and they will not be rewarded
for them with bliss or with reduction of the punishment. End quote.

Shaykh Ibn Baaz
(may Allah have mercy on him) said:

Whoever doubts
the hereafter and doubts whether Paradise exists or not, or whether Hell
exists or not, or whether there will be a resurrection or not, or whether
Allah will resurrect the dead, has no faith or certainty. Such a person is a
disbeliever until he believes in the resurrection and in Paradise and Hell,
and that Allah has prepared Paradise for the righteous and has prepared Hell
for the disbelievers. It is essential to believe in that, according to the
consensus of the Muslims.

End quote from
Majmoo‘ Fataawa Ibn Baaz (28/231).

Shaykh Ibn
‘Uthaymeen (may Allah have mercy on him) said:

Allah often
mentions belief in Him, may He be exalted, alongside belief in the Last Day,
and belief in the initial creation alongside belief in the re-creation
(resurrection), because whoever does not believe in the Last Day cannot be a
believer in Allah.

End quote from
Majmoo‘ Fataawa wa Rasaa’il al-‘Uthaymeen (8/472).

And Allah knows
best.

See also the
answers to questions no. 12295,
12347 and 13994.