In Act 2, Part 1, Sir Robert Chiltern woefully describes how Baron Arnheim seduced him with talk of power and wealth—talk that ultimately convinced Robert to sell a government secret to Arnheim in order to give momentum to his own political career. With considerable verbal irony, he recounts his experience of Arnheim’s persuasion using the language of philosophy and religion:
With that wonderfully fascinating quiet voice of his he expounded to us the most terrible of all philosophies, the philosophy of power, preached to us the most marvellous of all gospels, the gospel of gold. I think he saw the effect he had produced on me, for some days afterwards he wrote and asked me to come and see him.
In the Christian culture of England at the time of Wilde’s writing, the gospel would have been seen as the message of the opportunity to find salvation through Jesus Christ. Robert’s use of the term "gospel" to describe the avaricious ideology of Arnheim, an ideology that is diametrically opposed to that of the gospel, thereby gains considerable verbal irony: at the point at which he tells this story to Lord Goring, he is consumed with regret over his actions. Τhe effect of this irony, and the tension between Christian virtue and Arnheim’s worldview, is therefore to underscore the religious fervor with which Arnheim spoke of wealth and power. It also shows the pull that Arnheim’s words must have had on Robert for him to be convinced to illegally sell information on the Suez Canal.
In light of Wilde’s own personal ambivalence toward religion, however, this passage may gain another level of irony: in highlighting how Arnheim and Robert both embraced this alternative "gospel," Wilde shows how fickle and arbitrary—if not downright damaging—humanity’s most fervent beliefs can be.