Another reason John wrote his first letter was to warn the church of the deceivers, the false prophets, who were in the world. The concept of what is truth and reality as opposed to what is falsehood and fantasy is at the core of the battle between good and evil. The devil is the master of lies and delusions who began to ply his trade in the Garden. John warns of the deceivers who are spreading their false messages. Today, John's warning is extremely relevant with so many false teachers and self-imagined prophets in the world. John reminds his readers of how to tell the difference between the true message and the false blustering.