The religious leaders tried to prevent the resurrection by posting a guard and sealing the tomb. When this failed, they orchestrated a cover up. Their lies kept the Jews in darkness, just as Satan’s lies keep unbelievers in darkness.
The appearance of the angel brought deathly fear to the unbelieving soldiers. Holiness should always have this effect. The women were also afraid, but were comforted by the angel.
We see that Christ was made guilty for the sins of His people and took their punishment. His resurrection proved He was justified, and we along with Him. There is no salvation without belief in a risen Christ.