To have a face like an angel implies that Stephen’s face was radiant or shining in some way, similar to the face of Moses after he came down from the mountain (Exodus 34:29–35).1 Such a shining face was the result of and confirmation that someone had spent time in the presence of God.2 It is important to remember that the members of the Sanhedrin were the ones who saw that his face was like that of an angel. Even before he began to answer their questions they could see there was something special about this man. Presumably Luke received this information from Paul who was likely present during the trial (Acts 8:1).3
15 Tous ceux qui siégeaient au sanhédrin ayant fixé les regards sur Etienne, son visage leur parut comme celui d'un ange.