Grade 3 and grade 9 actually symbolize the trinity, which is a basic doctrine of Christianity. Senior angels, blazing angels, intelligent angels and archangels belong to the category of the Holy Father. It is said that such angels are made of fire (or light). The angel in the middle, the Lord angel, the angel of power and the angel of power belong to the class of children; Lower angels are correct angels, while archangels and angels are the classes of the Holy Spirit.