Is God Pure, Good, Loving and Fair?
Allah tells us He is Pure, Loving, and absolutely Just in every respect. He says He is the Best of Judges. He also tells us the life we are in here is a test. He has created everything existing and He created whatever happens as well. There is nothing in this existence except what He has created. He also says in the Quran He created evil (although He is not evil). He is using this as one of the many tests for us.
The Question of Justice
Consider people who do so much evil in the earth and then live to a ripe old age in the splendor and wealth of their ill-gotten gains and die without ever being taken to task for their deeds. Where is the justice or fairness in this? Allah provides a clear answer for us in Quran as to what is in store for these most evil of people:
A brief enjoyment in this world! — and then unto Us will be their return, then We shall make them taste the severest torment because they used to disbelieve.
[Noble Quran 10:70]
That Day mankind will proceed in scattered groups that they may be shown their deeds. So whoever does good equal to the weight of an atom, shall see it. And whoever does evil equal to the weight of an atom, shall see it.
[Noble Quran 99:6-8]
The Test of This Life
Do people think that they will be left alone because they say: “We believe,” and will not be tested. And We indeed tested those who were before them. And Allah will certainly make (it) known (the truth of) those who are true, and will certainly make (it) known (the falsehood of) those who are liars.
[Noble Quran 29:2-11]
Reward and punishment are definitely a part of the Next Life on a very permanent basis. Those who suffer in this life and seem to have nothing to show for all their hard works, good deeds and sacrifices and maintaining the faith can look forward to a far greater reward in a place where these things will not be temporary but rather they will be for eternity. Those who corrupt, violate, injure and do evil and destruction seem to escape any justice here, yet in the Next Life they too will see the fruits of their labors, and certainly they will be paid according to what they have done as well.
As regards oppression, this is something Allah forbids for Himself to do to anyone and He hates it when anyone oppresses someone else. He does have absolute power over everything. He allows sickness, disease, death and even oppression so we can all be tested in what we do.