In the apostles Creed we say:
was crucified, died and was buried; he descended into hell
Today we continue the fast, if possible, from yesterday until after the Easter Vigil because we are reflecting on that descent in to hell. We do not mean hell in the Christian sense of eternal separation from God because of the choices people made during their earthly life. Here we mean Sheol, the place for all the dead. Until Jesus death and resurrection, even the thought that a human being could be eternally in the presence of God was unthinkable.
Today we mark that moment when Christ entered what is Hebrew was called Sheol, in Greek Hades, and prepared to take with him every righteous soul ever created who had died before him. He broke the chains of death, and unlocked the gates of heaven, making possible for human beings to enter into heaven. Abraham, Sarah, Moses, the prophets and prophetesses and all the countless unnamed righteous men and women from the creation of the world who strove to do God's will.
We are reminded once more that God is not bound by time and space. The mercy of God is truly limitless.