Saint Gregory of Nazianzus

Gregory the Theologian (Gregory of Nazianzus), by Andrei Rublev (1360s–late 1420s). From Wikipedia.

O God, who hast enlightened thy Church by the teaching of thy servant Gregory Nazianzus: Enrich it evermore, we beseech thee, with thy heavenly grace, and raise up faithful witnesses, who by their life and doctrine may set forth . . . → Read More: Saint Gregory of Nazianzus