I believe the devil exists because the scriptures say that he exists. Furthermore, I have done business with him—and I am not being entirely tongue in cheek.
First, the devil is a creature. He is a created being who, by his own volition, turned bad. As a creature, he is limited. He is not equal to God in power or cunning. I like thinking of the devil as a mad dog on a very long leash.
The Bible says he disguises himself as an “angel of light.” I will refer you to II Corinthians 11:14. We can forget those cartoonish images of a bearded man decked out in a red union suit with a bifurcated tail and pitchfork. He is cunning. He is powerful. And he has been around for longer than you or I could imagine and he has legions of demons in his league, but, again, he is no match for God.
He is a tempter. But the world and, indeed, even our own passions and lusty imagination, provide plenty of fuel for temptation, too. In other words, we are to give the devil his due, but let’s not give him more than his due. Do not go around looking for the devil beneath every bed, inside every cupboard, or behind every door, but do not be ignorant of his methods of trickery and be on guard for his well-placed traps.
The Bible says if we resist the devil, he will flee (James 4:7). We are to ignore the subtle messages which reek of smoke and brimstone. We are to steer clear of his snares. And we certainly do not want to linger over the temptations he places before us.
We can guard our minds and our hearts by mediating on God’s word and conversing with Him through prayer. This is a good “how to” formula for resisting the devil.