Another resource that has served many well in the quest to find answers to many of the common questions regarding Christianity, including the notion of exclusivity, is Lee Strobel’s Case for Christ.

Strobel himself was an atheist who set out to disprove the primary beliefs of Christians.  Well, in the process he saw the overwhelming evidence for the person and work of Jesus and became a follower of Christ.

Several other apologetic resources can be found at his website.