How can one convince his wife to change her short attire, to which she has become accustomed and which is displeases God, without a dispute, bearing in mind that the marriage contract has been concluded but the marriage has not yet been consummated?

The Prophet Muhammad, peace be upon him, guided us to choose a religious wife. Your acceptance of a proposal from a woman who displays her adornments, and your failure in choosing, now requires you to make clear to her that the hijab (definition) is a command from Allah Almighty for believing women, and not merely a custom. And that a Muslim is commanded to submit and surrender to Allah's rulings. Allah Almighty says: "It is not for a believing man or a believing woman, when Allah and His Messenger have decided a matter, that they should [thereafter] have any choice about their affair. And whoever disobeys Allah and His Messenger has certainly strayed into clear error." Be keen to encourage her to keep company with righteous women, help her turn to Allah, and seek Allah's help and supplicate to Him with earnest prayer.