This is a very important matter. The Prophet (peace be upon him) said, “Whenever a non-Muslim (or a non-believer) does a hasanah (a good deed) in this life, he will be rewarded accordingly in the life of this world.” This is the divine justice. Whoever does good shall be compensated with what is good.
Then, he has no share in hereafter. “And whosoever does good while he is a believer, he is rewarded for in this life in addition to the reward which Allah (Glory be to Him) has saved for him in the hereafter.” So that, he will be rewarded for his good deeds twice, which would -with the grace of Allah- will admit him to Paradise. Allah (glory be to Him) says in Surah Al-Kahf,
Say, [O Muhammad], “Shall we [believers] inform you of the greatest losers as to [their] deeds? [They are] those whose effort is lost in worldly life, while they think that they are doing well in work.” Those are the ones who disbelieve in the verses of their Lord and in [their] meeting Him, so their deeds have become worthless; and We will not assign to them on the Day of Resurrection any importance. (Al-Kahf 18:103-105)
These verses are very clear in explaining the fate of those who used to think in the life of this world that they are doing very well. They are very hard workers, as far as worship; going to the places of worship on a regular basis. But, they are worshipping other than Allah. Either they are worshipping human beings, animals, idols, pictures or images. It does not matter. As long as they do not worship Allah (Glory be to Him) alone, Allah, the Almighty says, “I am so self-sufficient that I am in no need of having an associate. Thus he who does an action for someone else’s sake as well as Mine will have that action renounced by Me to him whom he associated with Me.” So, setting partners to Allah in worship will make the person not eligible for Allah’s Mercy whatsoever. In Surah Al-Nisa’, Allah (Glory be to Him) repeated this twice in two different verses, in verse number 48 and another verse afterward, it says:
Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills. (Al-Nisa’ 4:48)
Then, anything other than shirk (disbelief), any sin lesser than shirk, if the person seeks forgiveness, he will be forgiven, but if the person is a mushrik, a non-Muslim or a non-believer, he is not eligible for forgiveness. He is not eligible for reward because he was not doing whatever he was doing for the sake of Allah. He was doing for the sake for whatever; dunya (worldly life) or other force he was worshipping. So that these forces, on the Day of Judgment, will be resurrected and their followers will follow them. They will lead them to the fire of hell. They will fall in it and will drag along with them those who used to worship them. May Allah (Glory be to Him) protect us!
But, as far as their compensation in the dunya, they shall receive their full compensation in the dunya without diminishing their reward the least because this is from the justice of Allah (Glory be to Him).
Watch Dr. Muhammad Salah taking about this issue.