there is no other means of entering into life unless she conceive us in the womb and give us birth, unless she nourish us at her breasts, and, in short, keep us under her charge and government, until, divested of mortal flesh, we become like the angels (Mt. 22:30). For our weakness does not permit us to leave the school until we have spent our whole lives as scholars. Moreover, beyond the pale of the Church no forgiveness of sins, no salvation, can be hoped for (Institutes Book IV, ch i, para 4)In simple words, people are always born and people have mothers. There is always blood and there is always water
Similarly, if people are to be re-born, they must have a new mother, and there must be blood and water.
Without a mother and without blood and water, there is no rebirth and no way we could
call God, Father.
Or as Paul puts it in Galatians 4, no mama = no papa.
HT: Toby S and Steve J