[quote="tonyrey, post:10, topic:242853"]
Even so it seems unjust that infants should be separated from God and their parents forever through no one's fault.
It is not unjust because every person is conceived in original sin and thus has no right to Heaven. When a person has no right to Heaven, it is entirely just for them to not go to Heaven. It is sanctifying grace, which we received through baptism, that gives us the right to go to Heaven.
It is a de fide teaching of the Church that all those who die in original sin along (i.e. no actual sin) descend immediately to hell. It is also a de fide teaching of the Church that, the only divinely revealed way to remove original sin is Baptism, or the desire therefore.
Therefore, it is a de fide teaching of the Church that, to the extent of our knowledge stemming from divine revelation, there is no way for deceased unbaptized infants to attain the Beatific Vision (i.e. Heaven). This is the constant teaching of the Fathers and Doctors of the Church.
Now here's the big "BUT" --
BUT, the fact that divine revelation has not revealed to us any way that unbaptized infants can be saved does not mean that God will not act to save these unbaptized souls anyway. Therefore it is permissible to hope that He does so. However, to claim to be certain that unbaptized infants go to Heaven is an error.
St. Augustine and other early Fathers believed that unbaptized infants suffered eternal torments in Hell. St. Thomas Aquinas and other medieval scholastics believed that unbaptized infants enjoyed a state of natural happiness, lacking only the Beatific Vision, which they called "Limbo of the Infants".
Personally, I do not think that unbaptized infants attain Heaven. The historical opinion of the Church speaks against it.