If Jesus is Messiah than how He died on the Cross ? Please read the details before answering.?

Jesus had the power to save himself from persecution and his execution on the cross, but he choose not to, in order to clean humanity of sin. That is what made him the messiah. And I don't think the cross was a test if he was a messiah, that was just a normal way of execution back then. Many thieves and killers were executed like that too and I don't think they were testing to see if they were the messiah also. Jesus died on the cross, and three days later rose to heaven, again more proof he is the messiah.