Note 3 at Mt 27:52: This was an amazing event that only Matthew recorded. This earthquake apparently rolled the stones away from many of the graves in the vicinity of Jerusalem, and some of the saints buried there rose from the dead. Even at the death of Jesus, such power was released that death lost its grip on its captives.

It is uncertain whether these resurrected saints died again or were caught up to God. If they were resurrected at Christ's death, then they would have had to die again, just as Lazarus or Jairus' daughter or the widow's son at Nain or anyone else whom Jesus had raised from the dead during His ministry. This was because Jesus was "the firstfruits of them that slept" (1Co 15:20, see also Ac 26:23). Jesus was not the first person physically raised from the dead, but He was the first person begotten from the dead never to die again.

If these people were not actually resurrected until after Jesus' resurrection when Matthew stated they came out of the graves, then they could have been resurrected with their glorified bodies never to die again.

At any rate, these saints went into Jerusalem after Jesus had been resurrected and appeared to many people. We can only guess at the effect this must have had.