Being "all-powerful" doesn't mean that God can just automagically slice through any and all contradictions.
Given that, we have to ask if God can really "prevent all suffering" without causing worse evils, e.g., removing our free will and making us just mindless automatons without moral responsibility. I think he does not wish to do that because he regards that as a much greater evil.
interesting thoughts Campion
Being all powerful doesn’t mean there are things God can’t do- We know He can’t lie- Can’t act contrary to His essence- His being-
He also can’t allow sin to go unpunished because it is against His moral nature to do so. Lik you said- The only way to prevent all suffering and evils would be to make us all basically robots with no free will choice- We woudl be forced to obey at all times in order to prevent evil from occuring- But since there is Evil- God MUST punish the evil for the sake of all, which is summed up nicely in the following:
{{Five: God’s commitment to each community, entails some actions on His part to maintain the basis of community.
God builds human society with structures of rewards, censure, legal process, accountability, correction, reform and reinstatement, reconciliation, and nurture. These structures serve (basically) to provide for continuance of human life under adequate conditions.}}
http://christianthinktank.com/whyjust.html