What should a husband do who promised his wife to change for the better and for her to tolerate his past shortcomings, yet she still demands a divorce despite his improved treatment and his drawing closer to religion?

Slandering people and seeking out their faults are grave sins, as stated in His Almighty's saying: "Woe to every slanderer and backbiter." One must repent to Allah and seek forgiveness from the person who was slandered. And that person should accept the apology, in compliance with His Almighty's saying: "and those who pardon the people—and Allah loves the doers of good." It is not permissible to seek a divorce without a legitimate Sharia excuse, and the mention of slander is not a legitimate excuse if it is abandoned and repented from.