The "breakthrough" of Jesus death was not just death alone but his resurrection on the third day after He was crucified. Jesus already knew this while He was still alive. He told His disciple to be ready when He returns on that day.

True enough He was raised from Death and He went to heaven and sat on the right throne of His Father. This only proves one thing. Nothing is impossible for the Almighty God. Jesus conquered death. This is the starting of Christianity and people believed He is the Son Of one and only God.