Would the failure to make up missed prayers out of laziness, after his repentance and commitment to prayer, be a reason for him not to be cured of his illness?

Prayer holds great significance in Islam; it is the second pillar after the two testimonies of faith (Shahadatayn) and the first deed of a Muslim to be scrutinized. Abandoning it out of denial is considered disbelief by consensus. As for abandoning it out of laziness, there is a difference of opinion among scholars, and severe warnings have been issued concerning it. One who abandons prayer must repent and make up all missed prayers. If the number of missed prayers is unknown, one should continue making them up until it is overwhelmingly probable that one has cleared their obligation, and this is the view of the majority of scholars. The lack of healing may be due to the ill effects of sin.