How does one actually grow in the Life of Grace, toward holiness - toward sanctity - toward the perfection of Charity? It can take a long time to find trustworthy, readable information by a Catholic for other Catholics looking to learn exactly how we can grow in prayer, in communion with God and one another as is our vocation. I’ll recommend a book below.
It is interesting that this forum has “Trust Levels”, whereby in levels, or stages, a member can grow in trustworthiness in and with the Forum.
It is interesting that human persons naturally can grow toward maturity in their human nature through “levels” or the “stages” or “ages” of a human person: a fetus in the womb, an infant in the mother’s arms, a child, an adolescent, a teen, a young adult, a mature adult.
And what about the spiritual life?
St. Teresa found seven “mansions” of spiritual life possible in a growing child of God, who is growing toward the most interior home, the center in the soul where “His Majesty” dwells. This is described in her book The Interior Castle. (The book can be found, for example, on Amazon - paperback or Kindle)
St. John of the Cross describes three major “levels”, or “stages” of the interior, spiritual life, within which are two transitional stages of “Dark Nights”: a Purgative Stage, leading to a Dark Night of the Senses, leading into an Illuminative Stage, leading to a Dark Night of the Spirit, leading into a glorious transforming Unitive Stage. This path leads, that is, to the full spiritual maturity of Union of the soul with the Triune God - our holiness with His. John of the Cross describes this progression in several works, including The Ascent of Mt. Carmel. (The book can be found also, for example, on Amazon - paperback or Kindle)
The Catholic Church has this spiritual wisdom entrusted to her, for us! This wisdom is God’s intention for us!
I recommend - for a beginner in this spirituality - a contemporary book, by a Catholic layman, describing this journey of stages, specifically for Catholic laity: Link to Amazon: The Ordinary Path to Holiness. (The EWTN “Bookmark” interview with the author on this book, on his website, is HERE.)
This ought to be taught in every Catholic parish! We Catholics need to learn how to really, actually grow in holiness - to become “a saint” as God calls us. All are called to Holiness, and the perfection of Charity, as the Vatican II Council taught.