Bringing the Gospel or unmasking plots?

Yes: we are living in the End time. Many people follow the devil in various ways: under many aliases, appearances and through organizations/companies. But what to do as a Christian? Hunting for every deception, group or plot to show the devil and his organizations really exist? Or rather showing the Gospel leading to eternal life when believing also in one true God and one Lord Jesus Christ as Jesus teaches and says in John 17:3? A search trough the Bible.