Someone asked me recently for the three books, besides the Bible, that taught me the most about defending my faith. I could not do it. Every time I got the list down to three, I had to cut one that changed how I think, so I stopped narrowing and kept them all.

• Mere Christianity by C.S. Lewis is where I would start with someone exploring Christianity. Lewis begins with ordinary human experience, including our sense of right and wrong, and works toward the Christian understanding of God and how we should live.

• More Than a Carpenter by Josh and Sean McDowell is a shorter introduction, focused on Jesus and the evidence for his identity and resurrection. It is small enough to read in an afternoon and hand to a friend.

• I Don't Have Enough Faith to Be an Atheist by Norman Geisler and Frank Turek makes a broader case, working through questions about truth, God's existence, and the evidence for Christianity. I value the way it develops the argument in steps, rather than treating each objection as an isolated question.

• The Case for Christ by Lee Strobel approaches the evidence through interviews with scholars. Strobel asks about the reliability of the Gospel accounts and the case for the resurrection, then gives the scholars room to explain their answers.

• Cold-Case Christianity by J. Warner Wallace examines the Gospel accounts using the methods he brought to his work as a cold-case homicide detective. Questions about witnesses, corroboration, and the handling of evidence give it a different approach from the other books here.

• Tactics by Greg Koukl is the most practical book on this list for having a conversation about faith. It helps with asking questions, understanding what someone means, and examining a claim without turning the discussion into a fight. Knowing an argument does not necessarily mean knowing how to bring it into a conversation.

• Love Your God with All Your Mind by J.P. Moreland makes the case that developing the mind is part of Christian discipleship. Reasoning carefully about what I believe belongs in my life as a Christian, including when no one is asking me to defend it.

• The Story of Reality by Greg Koukl presents Christianity as an account of the world, from its beginning through its final resolution. It helps explain how the beliefs fit together, which can get lost when a conversation moves from one objection to the next.

• Seven Days That Divide the World by John Lennox addresses Genesis and science, including different interpretations of the creation account. Science comes up more than any other subject when people find out I take Christianity seriously, and I appreciate Lennox's care with both the biblical text and the scientific questions.

• Can Science Explain Everything? by John Lennox is a shorter book on the relationship between science and Christian belief. It examines what science can explain and whether those explanations leave any reason to believe in God. I would suggest this one for someone who wants to begin with that question rather than the interpretation of Genesis.

If I had to give someone just three to begin with, I would choose Mere Christianity for an introduction to the faith, I Don't Have Enough Faith to Be an Atheist for a fuller examination of the arguments, and Tactics for someone who already believes but goes quiet whenever the subject comes up.