Only one man conquered death and

His name is Jesus Christ. This was the sign of His deity, that He is God. Those who believe in Him have passed from death unto life. He declared, “I am the resurrection and the life. Anyone who believes in Me will live, even after dying.. (John 11:25)

We know the resurrection is true is because responsible & reliable eye witnesses said, “I saw Him, I looked upon Him”

1 Cor 15:7-8 Then He was seen by James and later by all the apostles. 8 Last of all, as though I had been born at the wrong time, I (apostle Paul) also saw Him.

we know the resurrection is true because lives are changed by it.