The other night, my Life Group got into a pretty challenging, sobering discussion on the biblical teaching of hell. Here are a couple of resources (one from Tim Keller, the other from John Piper) on the doctrine of hell, and why it is important:
The Importance of Hell, by Tim Keller
The Echo and Insufficiency of Hell, by John Piper
And I'm always mindful of a statement from Don Carson on this subject (I'm paraphrasing): if we can discuss or think about these things without tears in our eyes, we betray the character of Jesus even though our doctrinal knowledge might be orthodox.