"Sihon would not grant Israel to pass through his territory. And he gathered all his people together, and went out against Israel to the wilderness, and came to Jahaz, and fought against Israel" (v. 23). This portrays something that actually may take place in the spiritual realm. We may speak to the evil spirits, asking them to give us a way through their territory, but this stirs them to fight against us.
Israel slew Sihon, took possession of his land, and dwelt in the land of the Amorites (vv. 24-32). This indicates that after we engage in spiritual warfare against the evil spirits, part of the territory of Satan in the air becomes ours. Throughout the centuries, some of the saints have fought in such a way against the evil powers in the air.
According to 21:33-35, the children of Israel also defeated Og, the king of Bashan. Bashan, which is mentioned several times in the Psalms, is a mountain standing in opposition to God's dwelling place. Thus, Bashan is a type of the satanic authority in the air.
King Og and all his people came to do battle against Israel at Edrei (v. 33). Jehovah said to Moses, "Do not fear him; for I have given him into your hand, as well as all his people and his land; and you shall do to him as you did to Sihon king of the Amorites, who dwelt at Heshbon" (v. 34). Therefore, Israel slew Og, his sons, and all his people, until there was none left, and possessed his land (v. 35).
If we understand these verses regarding the three gate guards as typifying the church's spiritual warfare against the evil spirits in the air, we will obtain much that is profitable from these verses. Today we must fight against the evil spirits and defeat them so that we may gain more territory for God's kingdom.
In our Christian experience we may not have much realization concerning the spiritual warfare about which we have been speaking. When we think of spiritual warfare, we may have in mind the warfare between our spirit and our flesh or the struggle against sin and worldliness. However, the war against sin, the world, and the flesh is the lower part of the spiritual warfare. The higher part of the spiritual warfare is the fighting in the spiritual realm against evil spirits and demons.
In the spiritual world there is a territory usurped and occupied by Satan and his followers. Paul had an excellent understanding of this and spoke much concerning it. Now we need to learn about this spiritual reality, which is Satan's kingdom, the kingdom of darkness. Within this kingdom there are the fallen angels and the demons. Whereas the fallen angels are in the air, the demons are in the water. Both the angels and the demons, as followers of Satan, are working on fallen human beings to make them subjects in Satan's kingdom. The fallen angels in the air—the rulers, powers, and authorities of the kingdom of Satan—rule the entire world, and the demons are their helpers, helping the fallen angels to usurp human beings. Thus, the kingdom of Satan comprises evil angels, demons, and fallen human beings.
The New Testament tells us that God has appointed His people to fight against the kingdom of Satan. He has assigned them the responsibility of engaging in spiritual warfare. The history of Israel's fighting against the Canaanites is a type, a picture, of the warfare raging today between us and the fallen angels and the demons. If we read Numbers 21 from this perspective, we will see a vision concerning spiritual warfare.