How can a father deal with his 12 and 19-year-old children who are negligent in performing prayers, given his feeling of responsibility and shortcoming towards them?

The parents' failure to command their children to pray from the age of seven is one of the main reasons for their later stubbornness.

Continue to advise them, guide them, and urge them to pray. You may be firm with them when necessary and compel them to go to the mosque.

Check on their friends and replace bad company with good. Accompany them to lessons, lectures, and gatherings of remembrance.

Strive in supplicating for their guidance, for the Quran encourages supplication for righteous offspring: "And make righteous for me my offspring."