The challenge, I think, lies at the extremes. There are some Christian leaders who never talk about Satan, and others who talk incessantly about him. You know what I mean. In the case of the latter, every time the toast burns or something doesn’t go their way, Satan is behind it and it’s time for an exorcism. Neither extreme is particularly helpful.
In a similar way, the greatest mistake I believe you can make with evil is to overestimate or underestimate its influence. It doesn’t have ultimate power, but it also isn’t powerless. Evil is active. And in some way, it’s probably influencing your thought life, ministry, and family right now. At least that’s what the scriptures claim. And Jesus himself acted as though evil was very real.