The heights of holiness are not visions or locutions, but the profoundly simple gaze of infused contemplation, what scripture and the saints call wisdom, the contemplation of the divine essence.
St. John of the Cross advises people to discard visions and locutions and lofty spiritual experiences because of the danger of grandiosity which in its is most extreme form is narcissism. The person may be profoundly dysfunctional in many aspects of their lives but they cling to their spiritual experiences or the experiences of other’s as a proof of their holiness or the correctness of their views.
In contrast, Saint Teresa Avila talks about the discernment of visions and locutions and other extraordinary spiritual phenomenon but the two balance each other out nicely. There is need of discernment of if God is speaking to me through this extraordinary mystical experience. A good spiritual guide is essential. Many times a good spiritual guide will have an intuition that the visions and locutions are completely disconnected from reality, and the person ought to set them aside.