Luke here records the accounts of two marvellous miracles. One is the recovery of a paralysed person and the other is the raising of a dead person back to life. It is clear from the accounts that the Christians in each location did not have the power to deal with the problems. In the first case, Aeneas had been bedridden for eight years and in the second case Dorcas had died. Their Christian friends were not able to cure Aeneas or to prevent Dorcas from dying. And that is the normal state of affairs in a Christian church.
We are not told if Aeneas was a disciple before Peter met him, so it is difficult to say much about him personally. It is the case that his name was identified with a Trojan hero, who despite his mythological exploits was unable to help his namesake. Thankfully for our Aeneas, the true Hero came to his aid.
Tabitha is different. She is one of five disciples in the Book of Acts whose name is given. Luke highlights her dedication in helping the poor and needy in a practical way, especially widows. Her method of service was consistent, costly and crucial. She did what she could do and she was loved for doing it. And when she died, it was recognised that she would be missed. She had lived in such a way that she was irreplaceable. It would be good to have this reaction from others when we leave this world.
Nevertheless these Christians were not living in normal times because it was a period in which Jesus was working in a special way through his apostles, one of whom was Peter. And we see here two examples of how Jesus did so. First, he used Peter to recover Aeneas and then to raise Dorcas from the dead. These activities were not proof that Peter had power in himself, but that he was a special representative of the risen Christ, one of his apostles. The outcome was that many people in both communities were converted through the blessing of Jesus from heaven.