I want people to see that Christianity claims to be true in the deep sense, and if it isn't, then it solves nothing at all.

Evil did not catch God by surprise. He had a rescue plan, and He's still in the process of working out His plan.

Christianity is actually "true Truth," as Francis Schaeffer used to put it. God really does exist, Heaven actually is real (along with Hell), Jesus really did live and He did the things the historical records - the Gospels - say He did, the resurrection of Christ really happened, and there really is hope each of us can count on for "the kind of perfect world our hearts have always longed for."

Every worldview has its ambiguities - debatable elements that people simply will not see to eye on. There's nothing wrong with that as long as the disagreement is principled and dignified. I actually think that arguments - as opposed to quarrels - are good things because they're the best way to figure out what's true. Share your reasons, listen carefully to each other, be nice, and may the best idea win.

Almost everyone agrees the world is not the way it ought to be. It's called the problem of evil.

Though it's hard to be completely certain about things like this, I have a suspicion that only someone with deep freedom (one who makes decisions for reasons that are his own) and who's also a moral being (can experience goodness) can have a meaningful friendship with God. If friendship with God and sharing in His happiness are good things (and it seems they are), then making a creature who could enjoy these things is also a good thing, even if it comes with a liability. There's a risk.

An alternate explanation is not a refutation.