Is abandoning the admonishment of those who curse religion, or throw away scriptures containing the name of God, or mock religion, considered an act of disbelief (kufr)?

Advising people, enjoining good, forbidding evil, and calling to Allah the Exalted are obligatory duties, indicative of Allah's desire for good for the one who performs them. These are communal obligations (fard kifayah); if no one undertakes them, every capable person incurs sin according to their ability. However, mere silence regarding an evil act is not absolutely considered an endorsement of it, nor is the silent person like the perpetrator of the evil in every respect. Silence may or may not be an affirmation. No statement is attributed to a silent person unless there are indications of consent. Attending a gathering where Allah's verses are disbelieved in or mocked does not absolutely expel a servant from the fold of Islam; rather, this occurs with consent to their words and approval of them.