For Holy Church, i.e. the spiritual building, in order to attain to secret joys, has only three gates, viz., faith, hope, and charity; the one to the east, the second to the north, and the third to the south. Surely the gate to the east is faith because through her the true light rises in the mind. The gate to the north is hope because, whoever, placed in sin, despairs of pardon is utterly lost to mercy. Hence it is needful that he who is destroyed through his own iniquity be restored to life through hope of mercy. The gate to the south is charity because it burns in the fire of love. Then the sun is led to its height in the noonday because through charity the light of faith is exalted in love of God and neighbor. Three gates open on the inner court because faith, hope, and charity lead to secret joys.
[St. Gregory the Great, Homilies on the Book of the Prophet Ezekiel, Tomkinson, tr., Center for Traditionalist Orthodox Studies (Etna, CA: 2008) p. 386.]