SYMEON THE NEW THEOLOGIAN [ix] (949—1022)
The moment the soul is touched by the grace of the Holy Spirit, it becomes aware of its own poverty and is filled with light. And it is then that the soul sees the light of God not with its eyes, but with the eyes of the Spirit. The more the soul is purified, the more it is capable of beholding God in the Spirit.
This knowledge of God is not something acquired by reason or study, but is a gift of the Holy Spirit. Just as the body cannot see without the eyes, so the soul cannot see God without the Holy Spirit. And when the soul is illuminated by the Holy Spirit, it is no longer possible for it to be deceived or led astray by anything in this world. It becomes filled with divine joy and peace, and it is no longer concerned with the things of the flesh or the passions.
For the true knowledge of God is not of this world; it is not something that can be taught in a book or passed down from one person to another. It is a divine gift, a grace that is given to the soul in its purity. When the soul is united to God, it knows Him as He is, and the light of divine knowledge fills it completely.