"I want to see God!"
When we enter the second mansions, moving closer to the center of our souls, we have made the resolution to seek God. His voice is faint--often we hear him only through the words of a holy person, book, or we are driven to seek him because of some sufferings.
Teresa compares souls in the first mansions to those born deaf and mute--they hardly know what they are missing and so are often not sad. But those in the second mansions have glimpsed something of what they could be--they have seen God, veiled in shadows, and desire more. This desire is like suffering, but it is the suffering of a free man in chains.
The way in which souls in the second mansion will grow is in prayer. They may have experienced vocal prayer or liturgical prayer previously: They were "raised Catholic" or "Christian" or participated in group prayer at some point. Now it is vital that they learn interior prayer: meditation, recollection, and how to make exterior prayers interior as well. This will be their blood supply in the spiritual life and will give them strength.
They need that strength very much, because in these second mansions they are still vulnerable to their old habits of selfishness and sin. They still desire things and worry about matters not of God.
Teresa therefore stresses two themes for these souls: (1) discretion and (2) perseverance. This is no time for extreme acts of mortification. These souls need to be led according to their strength along the path of prayer: this requires some deliberate ordering of the exterior life. Set times of prayer, participation in the liturgy (Carmelite liturgy is markedly simple, bare, and focused on God rather than decorative arts), and a program of spiritual reading can all be gently implemented to bring the soul peace in its thirst for God and fear of sin.
Perseverance is key: Violent bursts of devotion followed by long stretches of tepidity can only dmage the soul and cause it to give up. A slow perseverance--a constant dependence on God's mercy and grace--is the only way for the soul to find its way deeper into its castle.
In spite of the seemingly endless nature of these mansions, Teresa urges her children to think mainly of that "glimpse" of total union with God that first impelled them out of the first mansions. Every soul should aspire to intimacy and the high adventure of sainthood--thinking nothing of what was left behind and pressing on to the highest heights of divine love. The emphasis should be on the total gift of self to God, mirroring God's own gift of self to us.