In that saint, you have a great treasure.

I was amused, daughter, how unjustly you complain, for you have your father friar John of the Cross there, who is a heavenly, indeed a divine man. Well, I assure you, my daughter, that since he went there to you, I have not found in all of Castile another person like him, who so ignites the path to heaven. You will not believe the solitude his absence here evokes in me.
Look, you have a great treasure in that saint, and let all in that house converse with him and discuss their souls with him, and you will see how advanced you will become, and you will find that in everything concerning spirit and perfection, you have made progress. Our Lord has indeed granted him a special grace for this purpose…

(Teresa of Jesus, letter to Mother Anne of Jesus in Beas, November 1578;
working translation of Vojtěch Kohut OCD)