I’m thankful you are concerned about your friend’s spiritual condition and are willing to answer his questions and tell him about Jesus.
Remember: Like every other person on earth, your friend has an immortal soul—a soul so valuable that Jesus Christ willingly gave His life to redeem it. Could anything be more important than sharing the Gospel with someone who doesn’t know Him?
Are you wasting your time? Sadly, some people will do anything they can to keep God at arm’s length (so to speak). However, I urge you to keep answering his questions until it’s clear that he’s only pretending to be serious about God. How can you discover this? One way is by focusing on Christ in your discussions, and not just on his minor questions. The central question he needs to answer is the same one Jesus asked His disciples: “But what about you … Who do you say I am?” (Matthew 16:15). This is the question you need to ask your friend—and if he refuses to face it, I seriously doubt his sincerity.
Let me also suggest that you ask him something else: “If I answered all your questions, would you be willing to give your life to Jesus? Or would you still refuse?” Even when some people admit the Gospel is true, they still resist Christ and are determined to run their own lives. Remember: Only God can break through the hardness of our hearts by His Spirit. Pray for your friend, that God will open his eyes and draw him to Jesus.