Any grace whatsoever that would have been granted to the person circuмcised in
the old dispensation would have been in anticipation of the grace of redemption
yet to come, which would not be until the Crucifixion.
But it is Catholic teaching that sanctifying grace cannot enter the soul so long as
mortal sin is there, which sin kills the life of grace in the soul. Original sin is not
exactly mortal sin, inasmuch as it is not personally committed by the soul who
has original sin, but the effect of original sin is the same as mortal sin, in that it
prevents the soul from receiving sanctifying grace; thus the need for baptism.
The only grace that such a one, with original sin, can receive is actual grace,
which has no enduring quality -- it is there one moment and gone the next.
Sanctifying grace is an enduring reality: it makes the soul a temple of the Holy
Ghost; but it can be lost too, in an instant, when the person commits mortal sin,
and then it cannot be restored until the person makes a good confession, or,
makes an act of perfect contrition - which is not an easy thing to do. Making an
act of perfect contrition is the fruit of immense actual graces, which Our Lady
provides to her children when she knows they are willing to receive it.
It is a most terrible thing to be denied actual grace from Our Lady, but sadly,
this does happen. She is perfect in her wisdom, though, and when she withholds
grace from a soul it is for their own good, as it were, for if she were to give them
grace they would then spurn and dishonor to their demise, the fact that they had
received the grace would put them into a worse place in hell.
Those who died during that age and were to be saved, could not be saved until
Jesus opened the gates of heaven by his sacrifice on the Cross, so those who
were to be saved went to the "bosom of Abraham," to wait for the life of grace.
That is why, at the moment Jesus died on the cross, there was a great earthquake
and many graves opened, and the just rose from them, and many were seen by
the living people, which struck them with a great fear.
Sorry, I don't have any authoritative author to quote, I'm going by catechism
lessons I learned years ago. This is just my opinion, and I could be wrong in
some detail, but I'm posting it because it's what I remember, and it seems right
to me.
The clearest case of anticipated grace is the Immaculate Conception of the
Blessed Virgin Mary. How could she have been spared original sin, when that
grace was not to be given to the world until her son, who was not yet born,
obviously, would die on the cross? She was given this singular privilege by the
infinite providence of God, by way of anticipation of her son's ultimate sacrifice.
In other words, she received a benefit from an event that would not happen yet,
for 48 or 49 years into the future (seven times seven).
The thing you describe as a new thing being taught in Catholic seminaries, is
disturbing, to be sure, but it's not entirely surprising. There are many such new
and erroneous teachings in so-called Catholic schools, so as to render them no
longer Catholic, and, as Bishop Sheen said so long ago, such schools are worse
than secular schools, for they attack the Faith of Catholics with a merciless
venom of corruption. He said that our children, sent to such schools, are most
likely to lose their faith.
There is a training program that "permanent deacons" (an oxymoron) go through,
which teaches them that small crumbs from the host that are too small to be
recognizable as bread, lose their character, and are therefore not the Eucharist.
This has never been the teaching of the Church, so why is it being taught to men
who are supposedly being trained to serve as assistants at the altar (the "table")?
I asked a good priest about this and he immediately replied that it is like saying
that a human embryo is not a person because it's too small to be recognizable
as such. I was very grateful for the analogy.