"Who are You Listening to?" is a great tool for starting a conversation about Christ, using the "Four Ultimate Authorities." Portions of this tract are from "The Gospel Time Line."* I love to use this tool to help a person see who and what they are actually trusting as a source of belief. It's a great lead up to presenting the Gospel.
*The Gospel Time Line is a 16 step (lesson) chronological approach to understanding the Bible from Genesis to Revelation. Written by Mark Manning. It is designed to be taught to those with little or no Bible background.