“Do you believe in Jesus?” seems like a strange question.

The question “Do you believe in Jesus?” is asking far more than “Do you believe that Jesus Christ existed/exists?” The true meaning of the question is “Do you believe Christ is who the Bible says He is, and are you trusting Him as your Savior?”

So, do you believe in Jesus?

Do you believe that Jesus is God in human form (John 1:1,15)? Do you believe that Jesus died on the cross to pay the penalty for your sins (1Corinthians 15:3; 2Corinthians 5:21), for which you deserve eternal separation from God (Romans 6:23)? Do you believe that the sacrifice of Jesus, God Incarnate, is the only adequate payment for your sins (1John 2:2; John 14:6; Acts 4:12)?

Do you believe these things? If so, great, but believing the facts about Jesus is only part of the equation. Biblical faith/belief is far more than believing certain things to be true. Biblical saving faith is also trusting/relying on those facts.