Why Worthing wants to arrange a christening?

Worthing thinks to get rid of Ernest. But, when he proposes to Gwendolen, she tells that she adores his name, and also, that their relationship would change if he had another name. That is why Worthing doesn't tell the true to her. As a consequence of that, he decides to be christened as Ernest and like this to change his real name. Although, he says to Chasuble, the clergy, that he arranges a christening because he doesn't know if he has been christened before. In conclusion, he decides to christened to change the name. Someone knows another possible answer?