believe it goes something like this:
Does not God have the right to take one lump of clay to create one vessel for mercy, and one for wrath. Can he not pour out his wrath upon the latter to show his greatness?
Also, look over the early parts of Romans 9.... specifically the Essau I have hated, and Jacob I have loved. That God choose Jacob before the foundation of the Earth, before either had done either good or evil, that the doctrine of predestination might stand.
I was once very hung over this idea. I spent a lot of time concerning myself with God's choice to create some people specifically for Hell, and others for Heaven. Lately, God has reminded me through his spirit and through other believers to not concern myself so much with this doctrine, but to preach repentance to those who are need it.
I pray that you do not stumble over this. For I stumbled greatly, thinking in my heart, this is not fair. I know look upon this as a means of remembering God's great mercy, that he choose a pathetic, proud sinner like me.
Also, look over Epheisans 1. The early verses deal with the fact that God predestines his chosen before the foundation of the world to conform to his image. It also states that God does this out of his own mere pleasure.