For those who wish to know the "intimate" St. John of the Cross, you probably could do no better than to read the very brief, but very rich "Sayings of Light and Love" from which the quotation below is extracted.
16. O sweetest love of God, so little known, whoever has found this rich mine is at rest!
Where your heart is, there is your treasure. Where your treasure is, so you will find your heart. I can think of no greater treasure than the love of God, and yet my heart dwells there so infrequently.