What is the ruling on a couple remaining bound by the marriage contract after the husband has sincerely repented of blaspheming Allah and abandoning prayer for years, and what is the ruling concerning the past years?

Whoever insults Allah the Almighty or abandons prayer out of denial has committed major disbelief (kufr akbar) and has exited the fold of Islam. As for whoever abandons it out of laziness, the majority opinion is that they do not commit disbelief that expels them from the fold of Islam. If a Muslim woman's husband disbelieves then repents before the 'iddah (waiting period) ends, the marriage contract remains valid and does not need renewal. However, if the 'iddah expires before his repentance, the marriage is annulled. If he wishes to return to his wife after that, a new contract is necessary. The previous cohabitation before knowledge of the marriage's invalidity is excused, and the child is attributed to both of them.