John of the Cross, even in his own time, presented unusual teachings, difficult to understand, accept and practice. Tke for example, inner silence of prayer/contemplation nad how it provides immunity from attacks from the devil be reducing the imagination and verbal thoughts to tamper with.
(See Book 3, chapter 4 :
“For the devil has no power over the soul unless it be through the operations of its faculties, principally by means of knowledge, whereupon depend almost all the other operations of the other faculties. Wherefore, if the memory be annihilated with respect to them, the devil can do naught; for he finds no foothold, and without a foothold he is powerless.”
and Chapter 6, #2
“2. In the second place, it is freed from many suggestions, temptations and motions of the devil, which he infuses into the soul by means of thoughts and ideas, causing it to fall into many impurities and sins, as David says in these words: ‘They have thought and spoken wickedness.’ And thus, when these thoughts have been completely removed, the devil has naught wherewith to assault the soul by natural means.”
pages 194-196
basilica.org/pages/ebooks/St.%20John%20of%20the%20Cross-Ascent%20of%20Mount%20Carmel.pdf
We all find it extremely difficult to practice silence, outer and inner. Even if we do not speak we usually have that inner monologue going on except in moments of pure attention. It takes faith to get through what seems to be a negative phase befor we realize the more subtle fullness of Christ already there all the time. There are so many distractions.