After noting the necessity of the “inward journey to the heart,” Nouwen immediately speaks of the dangers inherent in the journey.
Consequently, we must not make the journey by ourselves. That is, we must not be left alone to try to sort out “the many voices” we hear as we seek to go more deeply into God. St. John told us to test the spirits, to see whether they are of God (1 John 4:1). Teresa of Avila and John of the Cross repeatedly warned against making the spiritual journey without guides.
This is not radically different from the way we treat other things that are significant. We don’t learn a trade or practice an art in isolation from the witness of those who have gone before us and the counsel of those who walk along with us.
So too, in the spiritual life, we do not make it up as we go along. Nouwen puts it this way, “We hardly need to emphasize how dangerous experimentation with the interior life can be” (p.xix). We can end up doing ourselves more harm than good. This is one of the great dangers with any spirituality that is overly subjective, private, and independent.
But any journey that holds potential value has real risks. Our journey into God is no different. The point is, we must not face those risks alone. We have the revelation of Scripture, the witness of tradition, and the counsel of our community to help us navigate our way into deeper insights.