AC 2854 - temptations & salvation; AC 2861 - becoming spiritual

AC 2854
. . . the arcanum of the Lord's coming into the world
is that He united in Himself
the Divine to the Human
and the Human to the Divine;
which could not be done
except through the most grievous things of temptations;
and thus that by that union
it became possible for salvation to reach the human race,
in which no celestial and spiritual, or even natural good,
any longer remained;
and it is this union which saves those who are in the faith of charity.

AC 2861
By truths of doctrine conjoined with good of life,
a person becomes spiritual.
All spiritual quality is from this.
. . .  those who have lived in mutual charity and in obedience
are of the Lord's providence and mercy
instructed in the other life,
and then receive the truths of faith easily,
and become spiritual.