The church is divided into nine bays, distinguished by four columns that form a square space in the centre and support the dome. The interior lighting, which creates a rich interplay of light with the mosaic decoration of the floor, the vaults and the sanctuary, is provided by the dome’s eight windows and the ogival-arched windows in the side bays and the apses, which are wider in the arms of the cross than in the four corners. The light penetrates and stands out on the mosaics that, attributable to Byzantine masters, cover most of the walls and vaults.
The entire sacred space, elevated by 26 centimetres, was separated from the rest of the church by the iconostasis, an enclosure, typical of Greek worship, made of marble slabs and aligned with the columns. An intense fragrance of incense spreads from this concealed space and reaches every corner of the church.
The Martorana floor tiles have intense colours and the lasting coolness of marble. The Martorana floor consists of eleven opus sectile panels, decorated with quincunxes and geometric motifs. The entire floor is made of white, porphyry, serpentine and antique yellow marble and is characterised by a strong adherence to the naturalism, typical of the Byzantine area, adopted from Cosmatesque and then Sicilian techniques.
The melody of Basilian chants welcomes the faithful who, already in the narthex, meet the two mosaic panels with scenes depicting Admiral George of Antioch kneeling before the Madonna and Roger II crowned directly by the hands of Christ. The sound and rhythm become louder and faster: the prayer reaches out directly to God through song and cheers the souls of the faithful who, with clasped hands, gaze at the grandiose Christ Pantocrator in the dome.