What Father Fuentès said in the actual text of his conference to the Mexican religious community certainly corresponds with the essence of what he heard from Lucia during his visit on the 26th of December 1957.

Here are some broad extracts of this interview such as it was published in the above-mentioned journals:

I wish only to tell you of the last conversation I had with her, on the 26th of December of last year.  I met her in her convent.  She was very sad, pale, emaciated.  She said to me:

Father, the Most Holy Virgin is very sad because no-one has paid any attention to Her message, neither the good nor the bad.  The good continue on their way, but without giving any importance to Her message.  The bad, not seeing the punishment of God actually falling upon them, continue their life of sin without even caring about the message.  But believe me, Father, God will chastise the world and this will be in a terrible manner.  The punishment from Heaven is imminent.

Father, how much time is there before 1960 arrives, and what will happen then?  It will be very sad for everyone, not one person will rejoice at all if beforehand the world does not pray and do penance.  I am not able to give any other details because it is still a secret.  According to the will of the most Holy Virgin, only the Holy Father and the Bishop of Fatima are permitted to know the secret, but they have chosen to not know it so that they would not be influenced.

This is the third part of the message of Our Lady which will remain secret until 1960.

Tell them, Father, that the Most Holy Virgin told my cousins Francisco and Jacinta, as well as myself, many times, that many nations will disappear from the face of the earth and that Russia will be the instrument of chastisement chosen by Heaven to punish the whole world if we do not beforehand obtain the conversion of that poor nation.  ( … )

Sister Lucy also told me:  Father, the devil is engaged in a decisive battle with the Holy Virgin, and as he knows what it is that most offends God, and which in a short space of time will gain for him the greatest number of souls,  he does everything he can to capture souls consecrated to God, because in this way the devil separates souls from their leaders, and thereby he can seize them more easily.

Here, the English version in the American review published by Father Ryan, Fatima Findings, in June 1959, is more precise:

That which afflicts the Immaculate Heart of Mary and the Heart of Jesus is the fall of religious and priestly souls.  The devil knows that religious and priests who fail in their beautiful vocation drag numerous souls to hell (…).  The devil wishes to take possession of consecrated souls;  he tries to corrupt them in order to deaden the souls of lay people in a final impenitence.  He employs all the tricks, even going so far as to suggest delaying entrance into religious life.  The result of this is the sterility of interior life, and among lay people, coldness regarding the subject of renouncing pleasure and total dedication to God.

This version was taken up by the magazine Messagero del Cuore di Maria, n°8-9, August-September 1961:

Tell them also, Father, that my cousins Francisco and Jacinta sacrificed themselves because in all the apparitions of the Most Holy Virgin, they always saw Her very sad.  She never smiled at us and this sadness, this anguish caused by offences against God and the punishments which menace sinners, penetrated our souls, and we thought only, with our childish little imaginations, of inventing different means of praying and making sacrifices.   The other thing which sanctified the children was seeing the vision of hell.   This is why, Father, my mission is not to tell the world about the material punishments which are certain to come if the world does not pray and do penance beforehand.  No.  My mission is to tell everyone about the imminent danger we are in of losing our souls for all eternity if we remain obstinate in sin.

Father, Sister Lucia also said to me, we should not wait for the Holy Father’s call to penitence for the whole world to come from Rome;  neither should we wait for it to come from our bishops in their dioceses, nor from the religious congregations.  No.  Our Lord has already, very often, used these means and the world has not paid attention.  This is why it is now necessary for each one of us to begin  to reform himself spiritually.  Each person must not only save his soul but also all the souls that God has placed in our path.

Here, the English version adds:

The devil does all he can to distract us and to take away from us the love of prayer;  we shall be saved together or we shall be damned together.

The initial text continues:

Father, the Most Holy Virgin did not tell me that we are in the last times of the world, but She made me understand this for three reasons.

The first reason is because She told me that the devil is about to engage in a decisive battle with the Holy Virgin, and a decisive battle is a final battle where one side will be victorious and the other side will suffer defeat.  Hence from now on we are for God or we are for the devil.  There is no middle course.

The second reason is because She said to my cousins as well as to myself that God is giving two last remedies to the world:  the Holy Rosary and the Devotion to the Immaculate Heart of Mary, These being the last two remedies, this signifies that there will be no others.

The third reason is because, as always in the plans of Divine Providence, God, before He is about to chastise the world, exhausts all other remedies.  Now, when He sees that the world pays no attention whatsoever, then, as we say in our imperfect manner of speaking, He offers us with a certain trepidation the last means of salvation, His Most Holy Mother.  It is with a certain trepidation because if you despise and repulse this ultimate means we will not have any more forgiveness from Heaven because we will have committed a sin which the Gospel calls the sin against the Holy Spirit.  This sin consists of openly rejecting, with full knowledge and consent, the salvation which He offers.  Remember that Jesus Christ is a very good Son and that He does not permit that we offend and despise His Most Holy Mother.  We have as testimony many centuries of Church history which demonstrate, by the terrible chastisements which have befallen those who have attacked the honour of His Most Holy Mother, how Our Lord Jesus Christ has always defended the honour of His Mother.

Two ways of saving the world, Sister Lucia told me:  prayer and sacrifice.

Regarding the Holy Rosary, look, Father, the Most Holy Virgin, in these last times in which we live, has given a new efficacy to the recitation of the Rosary.  So much so, that there is no problem, no matter how difficult it is, whether temporal or, above all, spiritual, in the personal life of each one of us, of our families, of the families of the world, or of the religious communities, or even of the life of peoples and nation, that cannot be solved by the Rosary.  There is no problem I tell you, no matter how difficult it is, that we cannot resolve by praying the Holy Rosary.  With the Holy Rosary, we will save ourselves, we will sanctify ourselves, we will console Our Lord and obtain the salvation of many souls.

Finally, the devotion to the Immaculate Heart of Mary, Our Most Holy Mother, consists in considering Her as the seat of mercy, of goodness and of pardon, and as the certain door by which we are to enter Heaven.