Tim Keller sermons via Gospel in Life: Modern people are uncomfortable with the existence of evil, let alone the existence of the Devil. Yet, the Bible teaches that we cannot fully understand the world we live in unless we realize that there are supernatural agents of evil. But it is not enough to believe in the Devil; a Christian must study his methods. Satan practices evil subtly. He tempts and accuses people rather than overthrowing their will. Temptation is when the Devil asks us to ignore the holiness of God. Accusation is when he blinds us to the love and grace of God.