Our sinful nature is incompatible with God and His will for our lives. That which we cannot set apart for His glory must eventually be dealt with. Israel had the “mixed multitude.” When you read Israel’s complaints during their journey from Egypt to the Promised Land, you will usually find the mixed multitude involved. The mixed multitude was also likely behind the golden calf incident.
The mixed multitude did not understand the spiritual things of God. They did not understand why God only gave them manna to eat in the desert. They wanted to go back to Egypt, where their carnal nature was easily satisfied.
They incited the Israelites to reject mana, the daily miracle of God’s provision, and to ask for meat instead. God granted that prayer, but it came at a terrible price. When we pray, we must ask that God’s will be done above our own.
The sinful nature is at home in Egypt - slavery, but the spiritual nature is adopted for the Promised Land - freedom.