What is the ruling on dealing with a man who embraced Islam and married a Muslim woman, but he does not pray or fast (due to diabetes) and does not fulfill the pillars of Islam, and his wife does not pray regularly nor does she wear the hijab?

Diabetes does not prevent prayer, but it may prevent fasting. In this case, feeding a needy person for each day is obligatory. A diabetic must pray and fast if able. If not, then feeding the poor is obligatory. Zakat is also obligatory if they possess wealth. If they respond and fulfill God's commands, especially prayer, otherwise, they are apostates. As for the wife who prays sometimes and neglects it at other times, and does not wear the hijab, she is in great danger. Some scholars consider whoever intentionally misses a single prayer to have committed an act of disbelief. Both spouses must be advised, and these rulings explained to them. Those who can influence them should be informed. They should be dealt with according to what serves the religious interest. If advice and kindness affect them, do not shun them. But if shunning and harshness lead them to repentance, then shun them.