Here is the news story: Boy Asks If Atheist Dad Is In Heaven [HuffPo] and here: ‘Is my dad in heaven?’ little boy asks pope [The Catholic spirit].
The Pope was not giving a precise theological answer. However, he clearly implied that atheists can possibly go to heaven. And that is my theological opinion also.
An atheist can enter the state of grace by a baptism of desire. An act of love is sufficient for the adult to obtain sanctifying grace and to supply the lack of formal baptism. The act of love in question must be true spiritual love, in full cooperation with grace. But it is possible. And by entering the state of grace in this way, the atheist has love, faith, and hope. He has faith in love, truth, justice, mercy, etc. — faith in the things that are of God. And this is an implicit type of faith in Christ and in God.
I can’t judge the soul of the father of that boy. And I notice that the Pope cleverly avoided giving a direct answer, so that he would not have to judge that particular atheist’s soul. But in general, an atheist who loves others selflessly can go to heaven. This father’s act of having his children baptized, could well be an indication of his implicit faith.
So there is nothing too controversial in the Pope’s words and deeds here. The Church has not decided this question, about the extent of an implicit baptism of desire, and how this might apply to non-believers. But the Pope’s position is not heretical; it is a tenable faithful opinion.
Ronald L. Conte Jr.
the reproach of Christ 
The risk with this sort of discussions is to promote the illusion that living a moral life and loving our neighbours is sufficient to gain salvation.
I myself heard many people saying that since they live a good life and hurt nobody, maybe even help those in need, then they have nothing to worry about their salvation, or to care for their spiritual life, or to worship God, if ever existed.
But we know that this self sufficient attitude simply is not catholic: being a good person according to human nature does not grant us any salvation. We need the Grace of God in order to bring our nature to perfection, otherwise we override the sacrifice of Christ and we affirm that salvation is something futile: we are saved on our own.
This is not to say that all those who do not believe are damned for ethernity, because God has infinite ways to apply the merits of Christ to whomever he pleases, by means of His Church in the first place (Ecclesia supplet). However, it is wrong to believe that being good is good for you in the long term. If it does not come from Christ, all the good of the world can only harm you if it prevents you to know Gesus Chirst and to hunger his love and forgiveness.
If a person loves their neighbor, in full cooperation with grace, then they have the state of grace. If they do good acts without grace, then all the exterior good acts in the world will not help them. So the question is whether the exterior good acts are accompanied by the interior cooperation with grace that causes these acts to be done out of love of neighbor.
If “Living a moral life and loving our neighbor” includes the full cooperation with grace, then the person is in the state of grace and so they are saved (if they die in that state). For persons who decline to become Christian or Catholic without the full culpability of actual mortal sin, love of neighbor and living a moral life may be sufficient. However, objectively, we all have an obligation, under pain of mortal sin of omission, to join the Church and live according to Her teachings.
Thank you Ron, but what do you mean exactly by “interior cooperation with grace”, referred to an atheist?
First, any person unrepentant from actual mortal sins, and therefore not in the state of grace, may cooperate with actual graces to some extent. So, when we apply this to an atheist, who have not yet entered the state of grace in some way, he can cooperate with actual graces. If he ever cooperates to a full extent, in an act of selfless love of neighbor, then (in my view) he enters the state of grace by an implicit baptism of desire. The state of grace given in baptism includes love, faith, and hope. He who desires selfless true love desires baptism implicitly.
How do you reconcile your interpretation of baptism by blood, and salvation for non-Catholics, with Pope Gregory XVI in Mirari Vos? Thanks.
13. Now We consider another abundant source of the evils with which the Church is afflicted at present: indifferentism. This perverse opinion is spread on all sides by the fraud of the wicked who claim that it is possible to obtain the eternal salvation of the soul by the profession of any kind of religion, as long as morality is maintained. Surely, in so clear a matter, you will drive this deadly error far from the people committed to your care. With the admonition of the apostle that “there is one God, one faith, one baptism”[Eph 4.5] may those fear who contrive the notion that the safe harbor of salvation is open to persons of any religion whatever. They should consider the testimony of Christ Himself that “those who are not with Christ are against Him,”[Lk 11.23] and that they disperse unhappily who do not gather with Him. Therefore “without a doubt, they will perish forever, unless they hold the Catholic faith whole and inviolate.”[Symbol .s. Athanasius] Let them hear Jerome who, while the Church was torn into three parts by schism, tells us that whenever someone tried to persuade him to join his group he always exclaimed: “He who is for the See of Peter is for me.”[St. Jerome, epistle 57] A schismatic flatters himself falsely if he asserts that he, too, has been washed in the waters of regeneration. Indeed Augustine would reply to such a man: “The branch has the same form when it has been cut off from the vine; but of what profit for it is the form, if it does not live from the root?”[St. Augustine, in psalm. contra part. Donat.]
The answer here is the same as for the teaching of the Council of Florence, which said that Jews, Muslims, heretics, schismatics, etc. cannot be saved unless they repent/convert. The Church speaks of objective mortal sin, it is always a type of sin that deserves eternal punishment, to know the Christian faith and not convert, or to follow another religion, knowing about Catholicism. But the person only goes to Hell if the sin has the full culpability of actual mortal sin, and the person does not repent. A person could have a sincere but mistaken conscience, in committing the objective mortal sin of following another religion, and then live a moral life, loving God and neighbor.
What the Pope is condemning is the idea that there is no objective mortal sin committed when following some other religion, as if it doesn’t objectively matter: indifferentism.