As for you, you were dead in your transgressions and sins, in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient. All of us also lived among them at one time, gratifying the cravings of our flesh and following its desires and thoughts. Like the rest, we were by nature deserving of wrath
Ephesians 2:1-3Both the Devil and the world, in temptations, attack our flesh, causing us to sin. Interestingly, the pentecostal tradition tends to focus on the Devil, the Fundamentalists focus on the World and the Evangelicals tend to focus on the flesh. A balanced view would be that all of these work on us, since they are mentioned together in this verse.
So then when someone comes to you with a problem, considering all these things is a good perspective.