Should a Muslim greet and congratulate his family on Eid, even if they call for taking the Quran and abandoning the Hadith, for the sake of minimizing discord and not inconveniencing them?

One must believe in the authentic Ahadith of the Messenger of Allah, peace and blessings be upon him, because they are a revelation from Allah. One who denies the Sunnah is a disbeliever and an apostate. The Qur'an and the Sunnah do not differ. The Messenger of Allah, peace and blessings be upon him, conveyed the Book, and the Book commanded obedience to him. The Sunnah interprets the Qur'an and clarifies its details and rulings. One must treat family kindly and invite them to follow the Sunnah.