AC 5893 - Remains are truths and goods stored in the interior person by the Lord.

AC 5893 [2-3]
Truths must be present in the natural mind
if good is to do its work,
and those truths must be brought into it
through an affection belonging to genuine love.
Everything without exception in a person's memory
has been brought into it through some love,
and having become joined to that love
remains in the memory.
This also applies to the truths of faith;
if they have been brought in through a love of truth,
those truths become joined to and remain there with that love.
Once they have become joined to it
the following is then the situation:
If the affection is evoked again,
the truths that have been joined to it
reappear at the same time;
and if the truths are evoked again,
the affection to which they have been joined
reappears at the same time.
This being so, when a person is being regenerated
- which happens in adult life
because he is unable before this
to think for himself about the truths of faith -
he is governed by angels sent by the Lord.
They govern him by maintaining in him the truths
which he has become convinced are truths,
and by maintaining in him
through those truths
the affection to which they have been joined.
And because that affection - an affection for truth -
has its origin in good,
he is then led step by step towards good.

A considerable amount of experience
has proved the truth of this to me.
For I have noticed
that when evil spirits have thrust evils and falsities at me,
the angels from the Lord present at the time
have maintained in me the truths implanted in me previously
and have thereby withheld me from those evils and falsities.
From this it has also been evident
that the truths of faith which,
through an affection for truth,
have become rooted in me
serve as a level into which angels can operate,
so that people who do not have this level laid down in them
cannot be led by angels
but allow themselves to be led by hell.
For without it
the operation of the angels
cannot become established anywhere
and so passes away from them.
That level for angels to operate into
cannot however be acquired
unless the truths of faith have been put into service
and thus have been implanted in the person's will
and through this in his life.
It is also worth mentioning
that when the operation of the angels
into the truths of faith present with a person 
takes place,
it is rarely plain to see, that is to say,
so plain that thought about the truth operated into is aroused.
Rather, a general notion of things
in keeping with that truth,
and the affection that goes with it,
is produced.
For that operation by the angels
is effected by means of an imperceptible inflowing which,
when a visual presentation of it is made,
looks like an inflowing beam of light.
That light is made up of countless truths present within good
which focus on one particular truth known by a person
and which, while they sustain the truth in him,
also sustain the love that belongs to that truth.
This is the way the angels raise a person's mind
above falsities and protect it from evils.
Yet the person is totally unaware of any of this.