By A.W. Pink
"I will not drive them out in a single year, because the land would become desolate and the wild beasts too numerous for you. Little by little I will drive them out before you, until you have increased enough to take possession of the land." (Exo. 23:29, 30). Thus it is with the children of God. If they had not enemies without and within, and oppositions in their way, there are some dangerous "beasts" that would be ready to "increase" upon them.
For instance, there is a beast which is called pride, which might grow upon you if you had no enemies to fight with. Hence, a thorn in the flesh was given to Paul that he might not be exalted above measure. Is not the thorn in the flesh well ordered, which prevents confidence in the flesh?
There is a beast called carnal security, which might grow upon you. But now there are enemies on all hands of you, to prevent your falling asleep, to keep you watching and waking, and constantly on your guard.