This is a difficult question to answer because it involves discussing some principles that the person you are witnessing to may or may not agree with. For example, does he or she agree with you that truth is knowable and that God would attempt to communicate with His people or that only one religion may be right? Usually, I start by acknowledging the difficulty of coming to an easy answer. However, I tell them that I do have an answer, and I am sure it is the right one because it is an answer based on evidence. What kind of evidence? Prophecy and its fulfillment (see question # 34), Jesus and His miracles, the resurrection of Christ, etc. Then I ask that person if he or she knows of these things happening in other religions.(1) The answer is invariably, "No." Then I point out that they have only happened in Christianity. If any religion were true, Christianity fits the bill.