The Apostles Creed goes back to approximately A.D. 700, although segments of it are found as early as the second century. This creed was not written by the apostles, but is generally recognized as being faithful to their teaching.
The statement “He descended into hell” was added to the original Creed some years later and has not been universally accepted. It is omitted in many versions of the Creed. However, the statement vividly expresses the full extent of Christ’s vicarious sacrifice, even suffering the torment of hell for all people.
The “Communion of saints” in the Creed refers to the fellowship of believers. It is not a communion with saints in heaven (a common misunderstanding) but of saints on earth at all times and in all places.