The thoughts of the last four pontiffs
Pope Francis
Homily during Mass at Santa Marta, December 11, 2014
There is so much closeness that God presents himself as a mother, as a mother in dialogue with her child. A mother when she sings the lullaby to the child and takes the voice of the child and makes herself as small as the child and speaks with the tone of the child to the point of being ridiculous if one did not appreciate the greatness that was present there.
Pope Benedict XVI
In the book God and the World (2001)
God is God. He is neither man nor woman, but is beyond gender. He is the totally Other. I think it is important to remember that for biblical faith it has always been clear that God is neither man nor woman but precisely God and that man and woman are his image. Both come from him and both are potentially contained in him.
John Paul II
Audience September 8, 1999, commenting on the Parable of the Prodigal Son
The merciful father of the parable contains within himself, transcending them, all the traits of fatherhood and motherhood. Throwing himself around his son's neck, he shows the features of a mother who caresses her son and surrounds him with her warmth.
Pope John Paul I
Angelus, September 10, 1978
We are objects on God's part of an everlasting love. We know: he always has his eyes open on us, even when it seems there is night. He is Father; more still, He is Mother.