The identities of the two persons on the right and left of Jesus is uncertain. Most likely they are either Moses and John (from the symbols above their heads), or Isaiah and Paul (from the inscriptions under their feet).
Jesus Alone

Auditorium Windows

Movable Window
The Spirit comes through the Word.
God gives his Spirit to the Church.
The Spirit gives candidates willingness to spread the gospel.

Which apostle a symbol represents is given in the bottom window of each column. These windows were in the Seminary chapel before it was renovated.