Another way to think about this would be to say that because we are Christians, Christ is our interpretive paradigm for all of Scripture.  Where there might be points of tension, God as revealed in Jesus' life death and resurrection should trump other pictures of the Father.

And since 'Christ died [out of love] for us while we were still sinners', and since 'God so loved the world that he gave his one and only son'… I'm thinking God loves the whole world even before they're 'in Christ'.  Are there apparent points of tension with aspects of the Old Testament? Yes. But Christ definitively reveals God, and Christ died for unrepentant people.  Therefore, God loves sinners.  In fact, our love can only ever be a response to God's love.  Therefore if God can only love those who have already responded… he can love no one.

My two cents.

-Daniel-