I liked Dr. Geisler's answer. However I think that he could have spent more time on the point he raised about God's absolute justice. I don't want anyone to go hell, especially someone I've known, loved, and/or interacted with. IT really comes down to the following question for a believer: "How much do you really trust God?" Do you trust him to go as far as believe that He is doing everything for the best - that he never makes a mistake or misstep? If you believe that then you don't have to worry about your loved ones. All we have to do is obey God and witness to everyone who we come into contact with - and if necessary use words! I would feel far worse realizing that I could have told someone about Jesus and they ended up going to hell without hearing about Jesus from me.
Faithful Thinkers: Video: Loved Ones in Hell