We often talk like that ourselves. We don't really believe that fire is a man. In the same way, evil and sin are sometimes given a personality. This helps us realise just how big sin is, and how dangerous sins are to our salvation. This is proved by comparing two Bible passages.
Sin is powerful and brings death.
Your life is a constant battle against sin. Sin is your real enemy, not a supernatural devil. Its original meaning was 'one who accuses'. That would be a big mistake. Judas later betrayed Jesus with a kiss.