Praise be to Allah

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

“Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life, and We will surely give them their reward [in the Hereafter] according to the best of what they used to do”

[an-Nahl 16:97].

Al-Haafiz Ibn Katheer (may Allah have mercy on him) said:

This is a promise from Allah, may He be exalted, to the one who does righteous deeds, which refers to deeds that are in accordance with the Book of Allah, may He be exalted, and the Sunnah of His Prophet (blessings and peace of Allah be upon him), whether that person is male or female, from among the descendants of Adam, and believes in Allah and His Messenger in his heart, that Allah will cause him to live a good life in this world, and will reward him in the hereafter according to the best of his deeds. The good life includes a life of comfort and ease in many ways. It was narrated from Ibn ‘Abbaas and a number of others that they interpreted it as referring to good and lawful provision. It was narrated from ‘Ali ibn Abi Taalib (may Allah be pleased with him) that he interpreted it as referring to contentment. Something similar was stated by Ibn ‘Abbaas, ‘Ikrimah and Wahb ibn Munabbih. ‘Ali ibn Abi Talhah narrated from Ibn ‘Abbaas that it refers to happiness. Ad-Dahhaak said: It is lawful provision and worship in this world. Ad-Dahhaak also said: It is doing acts of obedience and finding comfort therein. The correct view is that the good life includes all of that.

End quote from Tafseer Ibn Katheer (4/516)

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

“And your Lord says, "Call upon Me; I will respond to you." Indeed, those who disdain My worship will enter Hell [rendered] contemptible”

[Ghaafir 40:60]

“But whoever desires the Hereafter and exerts the effort due to it while he is a believer - it is those whose effort is ever appreciated [by Allah ]”

[al-Israa’ 17:19]

“But he who does of righteous deeds while he is a believer - he will neither fear injustice nor deprivation”

[Taa-Haa 20:112].

These verses indicate that if a person believes in Allah, may He be exalted, and strives sincerely for his Lord’s sake, and does not associate anyone else in his worship, and adheres to the laws of Allah, and does not stray from that, then he will attain happiness in both realms, and will attain success in this world and the hereafter. One of the greatest blessings of this world that he can attain is to be blessed with peace of mind, a feeling of comfort and a life of ease, focusing on his duties towards Allah, having strong faith and certainty, without anything to distract him from that; rather Allah will bless him with a heart that is pure and clean, and will enable him to speak in a manner that is proper and good, and to do righteous deeds, and He will save him from temptation, confusion   and fitnah, whether apparent or hidden.

If he dies like that, then Allah will save him from the trial of the grave, and when He resurrects him, He will make the reckoning easy for him and grant him a multiple reward, and turn his bad deeds into good deeds, then He will admit him to Paradise by His mercy. There he will be happy and never be sad, he will live and never die, and he will find in it that which no eye has seen, no ear has heard, nor has it ever crossed the mind of man.

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

“Indeed, those who have said, ‘Our Lord is Allah’ and then remained on a right course - the angels will descend upon them, [saying], ‘Do not fear and do not grieve but receive good tidings of Paradise, which you were promised.

‘We [angels] were your allies in worldly life and [are so] in the Hereafter. And you will have therein whatever your souls desire, and you will have therein whatever you request [or wish].

As accommodation from a [Lord who is] Forgiving and Merciful’”

[Fussilat 41:30-32].

And Allah knows best.