I am always thinking. If GOD knows everything, (Since he's the God), what's OUR purpose? He already knows that what will happen next, regardless of what choice I make, he knows. So what's the WHOLE purpose?
Another thing, Person A, was born in a wealthy family. He had all the things he would need in this world. He decided to be really religious, and Islamic, and thankful to God, he devotes himself in the path of religion. But he still enjoys the luxuries gifted to him.
Person B is born in a needy family. He has 6 siblings, with 2 parents, all to take care of. Now everything is going against him, depending on the environment, he's NOT SO religious, he doesn't have time, and his stress doesn't allow him to do that. He's always thinking about his family. He doesn't pray, fast, and even has started to drink.
Person A goes to heaven. Let's suppose Person B also goes to heaven (Since he served his family), now they both stand on the same place.