Handbook of ROCOR Liturgical Practice:

When reading the Apostle or Gospel, how are the sainted authors to be named?

When introducing the Apostle and Gospel readings, we do not introduce the word ‘Saint’ into their titles. The readings are introduced as in the following examples:

For the Apostle: The reading is from the epistle of the Holy Apostle Paul (not ‘St Paul’) to the Corinthians.

For the Gospel: The reading is of the Holy Gospel according to Mark (not ‘St Mark’).

An exception for St John the Theologian: While liturgically the authors of the first three Gospel accounts are referred to solely by their names (Matthew, Mark, Luke), we affix the title ‘the Theologian’ to the name of St John in the following manner:

Deacon: Bless, Master, him who proclaims the Good Tidings of the Holy Apostle and Evangelist John the Theologian.
Priest: May God, through the prayers of the Holy, Glorious and All-Praised Apostle and Evangelist John the Theologian grant thee…
And then, just before the reading:
Deacon: The reading is of the Holy Gospel according to John (here without affixing ’the Theologian’).