Who knows?
"He descended into hell..." Apostles Creed
Between Good Friday and Easter Sunday, there is what we awkwardly refer to as Holy Saturday. "Holy" in what way? you may ask. When something or someone is deemed "holy", a special quality of purity, or elevation for higher purposes, is implied... Which renders its application to this particular occasion all the more suggestive.
Where was Jesus between Good Friday and Easter Sunday? According to tradition, enshrined in the Apostles Creed, he descended into hell. This is not a biblical assertion, but it was made by those who were anxious to keep the faith of believers focused on the Bible and to protect those same believers from the false claims of heretics (whose reinterpretations continue to lead people away from the established path of orthodox belief).
The statement that Jesus "descended into hell" seems to be based on references made in passages such as 1 Peter 3. 18-22 and led to the medieval doctrine (belief) of the "harrowing of hell", in which Jesus is supposed to have secured his victory over sin, death and the devil by bursting open the gates of hell and preaching the Gospel to those languishing therein. There are complicated arguments for and against this belief, as there are about what the original Greek and Hebrew words for "hell" (Hades and Sheol respectively) mean.
Suffice to say that the absence of Jesus between his death on Good Friday and his resurrection on Easter Sunday means that he shared the experience of mortality which is common to all humanity. And then he broke its power by returning to life in a completely new way. In anticipation of Easter, pause in awe and wonder... and perhaps discover why today is called "Holy Saturday".