St. Thomas, Patriarch of Constantinople, was a deacon, and then, under the Holy Patriarch John IV the Fasterer (582-595), sacellary (sacristan) in the Great Church of Constantinople. After the death of the Holy Patriarch Cyriacus (595-606), Saint Thomas was elected to the Patriarchal throne of Constantinople in 607. The saint took full care of the spiritual needs of the flock.

During the patriarchate of St. Thomas, a terrible sign appeared in the Galatian country (Asia Minor). The heavy crosses that were carried during the procession began to waver, bump against each other and break apart for no apparent reason. The well-known visionary elder, the Monk Theodore Sikeot, summoned by the patriarch (April 22), explained the meaning of the sign. According to him, the Church was in for strife and troubles, and the state was on the eve of ruin from a barbaric invasion. Upon hearing this, the saint was horrified and asked the Monk Theodore Sikeot to pray for him so that God would take his soul before the predicted ruin happened.

After the death of the Holy Patriarch Thomas (+ 610), disorganization began in the Church. The successor of St. Thomas, Patriarch Sergius (610-638), fell into the Monothelite heresy. Soon, by God's permission, a difficult war with the Persians began for Byzantium for the multiplication of heresies. The Greek regions in Asia Minor were completely devastated, Jerusalem fell, and the Life-giving Cross of the Lord was captured and taken to Persia. So all the misfortunes foreshadowed by a miracle during the procession came true.