I read both links. Neither is convincing. One explains how a contemporary Russian Orthodox priest teaches those in mortal sin may get out, but he doesn't back this up with Early Church Fathers.
The other link about Catholics in Para 1031 of RCC Catechism, I agree with Papist, does not indicate mortal sin can be forgiven.
Are there any Early Church Fathers who teach that those who died in serious sin can get out of hell?
I'll offer this:
Fr. Seraphim Rose in "The Soul After Death" pg. 204 tells of St. Gregory the Great (a Pope of all things) praying for a pagan to get out of hell. But even St. Mark Ephesus at Council of Florence indicated only those who have light sins can benefit from prayers or Sacrifice for those in Hades.
Kaste, I have an uncomfortable feeling that you don't really want to hear what the Orthodox believe. So please just take it from me that we believe that the eternal fate of souls is not fully decided at the time of death and the Partial Judgement. Until the end of time and the return of Christ our Lord there is a possibility of change.
Roman Catholics also believed this, when there were happier times and they were united with us.
A remnant of their old orthodox belief remains in their liturgy for the dead but now reinterpreted:"Libera animas omnium fidelium defunctorum de poenis inferni et de profundo lacu."
The Catholic Encyclopedia says: ----- "In itself, it is no rejection of Catholic dogma to suppose that God might at times, by way of exception, liberate a soul from hell.
Thus some argued from a false interpretation of 1 Peter 3:19 sq., that Christ freed several damned souls on the occasion of His descent into hell. Others were misled by untrustworthy stories into the belief that the prayers of Gregory the Great rescued the Emperor Trajan from hell. But now theologians are unanimous in teaching that such exceptions never take place and never have taken place, a teaching which should be accepted.
" If this be true, how can the Church pray in the Offertory of the Mass for the dead: "Libera animas omnium fidelium defunctorum de poenis inferni et de profundo lacu" etc.? Many think the Church uses these words to designate purgatory. They can be explained more readily, however, if we take into consideration the peculiar spirit of the Church's liturgy; sometimes she refers her prayers not to the time at which they are said, but to the time for which they are said. Thus the offertory in question is referred to the moment when the soul is about to leave the body, although it is actually said some time after that moment; and as if he were actually at the death-beds of the faithful, the priest implores God to preserve their souls from hell. But whichever explanation be preferred, this much remains certain, that in saying that offertory the Church intends to implore only those graces which the soul is still capable of receiving, namely, the grace of a happy death or the release from purgatory."
Imprimatur. +John Cardinal Farley, Archbishop of New York.http://www.newadvent.org/cathen/07207a.htm