And if you're the enemy one way you help enforce that rule is to keep your opponent off-balance by obfuscating your true goal and intentions. Look at how much effort the adherents to Islam make to come across not as the enemy, but as misunderstood worshipers of a religion and god of peace.
Or how much communists have invested in hiding their goals in the language of liberalism and progressives.
Satan has a lot of names in the Bible, but the one that best describes him is almost certainly the one that identifies him as the Father of Lies. His favorite trick to to convince those whom he would beguile that he is their friend, and has only their good in mind. It started with Eve, when he convinced her God had given the instructions regarding the forbidden fruit, not for her benefit, but because of His selfishness, wanting to keep its power for Himself. IMHO it's pretty telling that Satan still depends on the very first ruse he's recorded using, projection, and it still works so well.
Again, IMHO, if you believe in, and trust God, and you don't perceive Satan as as certainly a source of evil in your life as you view God a source of good, then you're cuisin’ for a bruisin’! And these are bruises that can last forever.
Great post