Many times in the first few years of my Christianity I tried to read John of the Cross but failed. Then, one day, as novice Capuchin friar on retreat in lovely Marathon, Wisconsin, I picked up The Ascent of Mount Carmel and read it freely. The moment had come for me to meet one of my great teachers. A few years later, having learned a little Spanish and finding myself as a student at the former Weston Jesuit School of Theology in Cambridge, Massachusetts, I went over to Shoenhof's and spent a large portion of my monthly 'day off' money on his Obras Completas.
It is often said in the spiritual life that God sends us guides and teachers at the moments when we need them. I have found this to be the case in my own life, and I believe it is one of the graces of the communion of saints. It's not limited to the Church on earth, however. We are also given saints to read at the right moments. That's why John of the Cross didn't work for me until I was ready. My first desires to read him were vainglorious; I thought I would read him because he was supposed to be deep and I wanted to be deep as well. When I had stumbled along long enough trying to live a life of prayer such that I could understand what John was talking about, then I was given the grace of being able to read him.
In this spirit we should be attentive if we have an inspiration to take up a devotion to a certain saint or to read his writings. God can also speak to us through others who suggest to us what we might read or with whom we might pray. The communion of saints is a way to talk about larger economies of grace working through friends of God across time and space, and it is a communion that is on our side in our desire for prayer and sanctity.
"Por ninguna ocupación dejar la oración mental, que es sustento del alma." ~Juan de la Cruz, Grados de Perfección, 5.