What does it mean that God is a Father?

I remember commenting to a girl one day about the idea of God that tormented her: “Your god is more or less like this, a sadistic parent who has filled the house with many jars of Nutella, of which you are very fond, and then has plastered the walls with signs like ‘do not touch,’ ‘attention, it is strictly forbidden to eat Nutella,’ ‘danger: Nutella is harmful!'”
She had confused God with her mother’s truly sadistic experience.
And with certain nuns from the kindergarten she had attended…
[…]
A God who dominates, enjoying putting tempting pleasures in front of us and then frightening us with a thousand prohibitions!
God opposed to pleasure.
God opposed to what I am most fond of.
God opposed to fun, life, the body, the senses, sex…
God opposed to me!
This persecutory idea of God is precisely what the Tempter insinuated into Adam and Eve.
It’s the eternal temptation…: to plan life “defending” oneself from God.

(MIMMO AND CINZIA ARMIENTO, Lascerai tuo padre e tua madre: dalla schiavitù dei bravi ragazzi alla libertà dei figli di Dio, Porziuncola, Assisi 2006, p.181)

[…] if they have not known You as a Savior through integral experience and understanding, they cannot testify for You and make You known to others.
Who has never tasted honey is not very convincing when trying to explain its flavor, and sooner or later, they get tired of giving these explanations.

(MARKO IVAN RUPNIK, Il cammino della vocazione cristiana : di risurrezione in risurrezione, Lipa, Roma 2007, p.97-98)

Whoever has not drunk wine does not get drunk by forcefully discussing wine […].

(ISAAC OF NINEVEH, Seconda collezione 18,2)

The fact that God revealed Himself as Father – and not as an ethical-religious entity – begins to fight against the lies contained in our fears.

(FABIO ROSINI, L’arte di guarire: l’emorroissa e il sentiero della vita sana, San Paolo, Cinisello Balsamo (MI) 2020, Kindle version, 44%)

[Believing in “God the Father”] is not a “pious sentiment,” but the only possibility we have to be content.
Certainly, one must have a faith that trusts.
And to have faith, it is essential that we frequently return to this question: “What has the Lord saved me from?” “What would I be without Him?” Answering sincerely and continually asking, remembering God’s goodness, is the beginning of authentic life.

(GIUSEPPE FORLAI, Vestirsi di luce : introduzione pratica alla vita nello Spirito, Paoline, Milano 2018, p.17)

How do we know […] that God, despite every appearance, does not play with the world at all but loves it and will always love it?
[…] God Himself had to reveal Himself, demolish the images, and introduce a new criterion of measurement. This happened in the Son, in Christ.

(JOSEPH RATZINGER, Il Dio di Gesù Cristo, Queriniana, Brescia 2012, p.30-31)

In Him crucified [man] discovers the true image of God, and the false image insinuated by the ancient serpent is washed away.
If he thought that God was jealous, not a giver, one who seeks to dominate, now he sees before his eyes a God who not only gives but gives Himself, who does not want to control and subjugate man but deems him worthy of His trust, to the point of entrusting Himself into his hands.
But since man is still an enemy of God, he destroys and kills Him.

(MARKO IVAN RUPNIK, Il cammino della vocazione cristiana : di risurrezione in risurrezione Lipa, Roma 2007, p.49)

“What do you want Me to do for you?”

(Mark 10:51)

[…] the question Jesus asks him is staggering: What do you want me to do for you?
This expression dismantles many deviations regarding the knowledge of God.
There is a real anguish in man at the thought that, if he knows God, he will have to serve Him, he will no longer be free. While [in this Gospel story] we have the blind man – an expression of all the poverty of man who cannot live according to his own knowledge, according to his own understanding, an expression of an injustice caused by this schism – standing before Christ recognized as the Son of David, and it is he, the Messiah, who now utters the typical phrase of every servant when called by his master: What do you want me to do for you? Here is the parable of the knowledge of God that gradually completes itself: God descends and goes to meet the man who cries out, presenting Himself to this man as a humble servant.

(MARKO IVAN RUPNIK, Dire l’uomo – Volume 1: Persona, cultura della Pasqua, Lipa, Roma 2011, p.181-182)

In this is love, not that we loved God, but that He loved us […].

(1 John 4:10)

To be sure of being loved,one must live an experience of love that is completely gratuitous, that is, one must not deserve love, be surprised by a crazy love, without measure, without possible justification (cf. Titus 3:5-7).
We must undergo the experience of a free love, and therefore according to the most authentic categories of mystery: that is, freedom, outside of every bond, every cause, every necessity…
It must be a total, boundless love.

(MARKO IVAN RUPNIK, Il cammino della vocazione cristiana : di risurrezione in risurrezione, Lipa, Roma 2007, p.52-53)

Why do I know that God is a Father? Is it because I like the concept or it warms my heart? No; I know because I have seen Him generate in me and in many people around me that life that does not come from man.
What we need is not to strive to be better or more consistent, or to discover some technique or follow some trendy personality, but to allow ourselves to be shaped by God.
It is about giving God permission to make you new, so that He can use you to experience His power as a Father.

(FABIO ROSINI, L’arte di guarire: l’emorroissa e il sentiero della vita sana, San Paolo, Cinisello Balsamo (MI) 2020, Kindle version, 74%)

As believers, we are convinced that, without an openness to the Father of all, there will be no solid and stable reasons for an appeal to fraternity. We are certain that “only with this awareness that we are not orphans, but children, can we live in peace with one another”. For “reason, by itself, is capable of grasping the equality between men and of giving stability to their civic coexistence, but it cannot establish fraternity”.

(POPE FRANCIS, Encyclical Letter Fratelli tutti, n.272)