As human beings, we tend to see from only a limited view. Imagine how scary it would be to have the weight of the world on our shoulders. No thank you. Lets entertain the thought for a moment that God would deal with all His creation with immediate justice. The wicked sin and Christians sin.
Sin is sin, yet there is an important and eternal difference.
Christians know the path of forgiveness. Sadly, the wicked do not. Look for a moment at another promise in this passage. Not in the long run. As created beings, we will all answer to the Creator.