The Sacraments needed for salvation are only dispensed by the Catholic Church, VISIBLY. Everyone outside It perishes.
How can one apply this to the opinion expressed here?
It is heresy. Plain and simple.
Baptism by water is, since the promulgation of the Gospel necessary for all men, without exception, for salvation.
This is DE FIDE teaching stated in the Council of Trent.
The Catechism of Trent gives the exact time water Baptism became obligatory on all men for salvation, with no exceptions. It states that: "from the time of Our Lord's Ascension into Heaven, it was then obligatory by law to be baptised for all those who were to be saved".
Trent Canon 2 on Baptism (see my signature) actually anathemized those who say that water is to be understood metaphorically or find any "substitute" for water or turn real and true "water" into a "figure of speech".
Also, those unbaptized persons in false religions, not being members of the Church, are definitely not subject to the Roman Pontiff but it is a defined dogma of the Catholic Church that no one can be saved who is not subject to the Roman Pontiff.
It is one of the requirements for salvation:
"We declare, say, define, and pronounce that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff."
(Pope Boniface VIII, in the bull, Unam Sanctam, 1302).
Unbaptized infants and little children who die are still in the state of original sin. Since no one can enter Heaven in state of original sin, these pour souls cannot be there. They are in Limbo. They do not suffer eternal fire and torment in Hell (only those beyond the age of reason, guilty of actual sins do). Their suffering consists only in the loss of the Beatific Vision.
Infallible Magisterium
Pope St. Zosimus:
"No one of our children is held not guilty until he is freed through Baptism".
Council of Lyons:
"The souls of those who die in mortal sin or with original sin only, however, immediately descend to Hell, yet to be punished with different punishments"
Council of Florence:
" It is likewise defined that the souls of those who depart in actual mortal sin or in original sin only, descend immediately into Hell but to undergo punishments of different kinds".
Pope Innocent III:
" The punishment of original sin is the loss of the vision of God; the punishment for actual sin is the torments of everlasting Hell".
One of the graces of Baptism is the remission of original sin.
Council of Florence:
"The effect of this sacrament is the remission of every sin, original and actual"