ANSWER: The answer is no they were not. The incident in question reads: "Jesus, when He had cried out again with a loud voice, yielded up His spirit. And behold, the veil of the temple was torn in two from top to bottom; and the earth quaked, and the rocks were split, and the graves were opened; and many bodies of the saints who had fallen asleep were raised; and coming out of the graves after His [Christ's] resurrection, they went into the holy city and appeared to many" (Matthew 27:50-53).
These saints were revived to a normal, physical life. The Scriptures show that there were other resurrections to temporary human life (I Kings 17:17-24; Luke 7:11-17; John 11:1-44; Acts 20:7-12). But like all those humans before and after them they all died once again. Jesus Christ is the only one ever resurrected to immortal life. He is the "firstborn among many brethren" (Romans 8:29). The Bible reveals that no one will follow Him into immortality until the resurrection at His Second Coming (I Corinthians 15:50-54; I Thessalonians 4:13-18; Revelation 20:4-6).