I've been listening to Therese of Avila's Interior Castle (it is a masterful work on prayer). One of the things that struck me was how easily she moves into prayer. She will be discussing a particular issue and then a few sentences later she is praising Christ or imploring him to make us experience what she is writing about.
This helps me understand how saturated she was in the Divine Life. She had our Lord constantly in mind and was aware of his presence in all things and had this deep and profound desire to please and serve him. It reminds me of Paul's letters where he calls himself slave of Christ. She calls Jesus, His Majesty.
She also lifts up the many ways we can grow slack in our prayer and let the Evil One distract us and keep us from growing deeper or, in her language, going into the next mansion. I know that it is easy to move away from our center and calling. There are so many good things to get distracted with. I find her insistence on prayer as primary in life to be so helpful.