The Holy Spirit’s appearance

Saint Gregory of Nazianzus says of the Holy Spirit’s appearance as a dove at Christ’s baptism:

And the Spirit comes as a dove, for he honours the body being seen “corpreally”, since He is also God by divinization. And since long ago the dove has been accustomed to announcing the good news of the flood’s end.
– Oration on the Holy Lights, 381 A.D.