Jesus died, there is no doubt, what happened next, is what the Gospel is about.
Christianity is unique among the religions of the world for many reasons, but one of the most important is that it can be disproven. The fundamental event of Christianity is the death, burial and resurrection of Jesus Christ (1 Corinthians 15:3, 4). There is no claim in the Koran that Mohammed physically rose from the dead after his death; neither is there a similar claim for Moses, the Buddha, or any founder of a major religion in the world today. The death, burial and resurrection of Jesus Christ, if they actually happened, separate Christianity from all other religions, and make Christ unique among religious leaders.
Anyone who wants to refute Christianity and make the Church wither and die simply has to prove that Jesus Christ did not die, at least not in the way that the Bible records, and did not physically rise again. In the two millennia since Jesus’ life, many skeptics have tried to disprove the Bible on this issue. None have succeeded thus far, but there are many theories about how Jesus did not really die as the Bible suggests.