How can one learn methods of Da‘wah to guide the family towards avoiding sins and committing to acts of worship without causing a negative reaction?

It is advisable to consult books such as "Usul al-Da'wah" (Principles of Da'wah) by Abd al-Karim Zaidan, "al-Da'wah ila Allah" (Calling to Allah) by Abu al-Fath al-Bayanuni, and the chapter on "Enjoining Good and Forbidding Evil" in the book "Al-Ihya".

One should supplicate for their relatives' guidance and repentance, advise them, remind them of Allah, His punishment, Paradise, and Hell, and explain the ugliness of neglecting prayer.

It is preferable to be gentle and lenient in da'wah, clarifying that the advice stems from a concern for their well-being and a love of good for them.