We're Our Own Worst Enemies

Nu 21-36 Like the Israelites, we're often our own worst enemies. Just as their complaining and their going after idols and immorality brought God's wrath against them, so we often seek after objects, accomplishments, and relationships, rather than God, in place of Him. We also indulge in sin of the mind and body and we're disssatisfied with where God's placed us, what He's given and withheld.
Though when others try to curse us as Balaam does Israel, God may, as He does with Balaam, not allow them to truly harm us, there seems little to protect us from ourselves.
I definitely would say it's my flesh, my sinful desires, my ambitions, jealousies, pride, that is most in the way of my spiritual growth.