TCR 374, 377 - the workings of charity with faith

TCR 374.
Charity is having good will,
and good deeds are doing good from a good will.

Charity and deeds are distinct from each other,
just as are the will and the action,
and as are the affection on the part of the mind
and the functioning of the body.
This is the same distinction as between the internal and the external person;
these are respectively like cause and effect,
since the causes of everything take form in the internal person,
and all the effects arise from this source in the external.
Therefore charity, being a quality of the internal person,
is having a good will;
and deeds, which belong to the external person,
are doing good from a good will.

. . . deeds in essence belong to the will,
in form to the understanding,
and in performance to the body.
That is how charity comes down to become good deeds.

TCR 377
Charity alone does not produce good deeds,
much less does faith alone,
but charity and faith together do.

This is because charity without faith is not charity,
neither is faith without charity faith . . ..
This is similar to the case of the will and the understanding.
The will does not exist by itself, so neither does it produce anything;
nor does the understanding exist by itself, or produce anything.
Everything that is produced comes from both acting together,
and is the product of the understanding activated by the will.
The reason why this is similar is
that the will is the dwellingplace of charity,
and the understanding is that of faith.
Faith alone is said to be much less productive,
because faith is truth, and its function is to create truths,
and these enlighten charity and its exercise.
The Lord teaches about this enlightenment when He said:

He who does the truth comes to the light,
so that his deeds may be made apparent,
since they are done in God.
John 3:21

When therefore a person does good deeds in accordance with truths,
he does them in light, that is to say, intelligently and wisely.