Is it permissible to attend mixed-gender wedding parties, then leave shortly after to offer congratulations and maintain kinship ties, given the parents' refusal to not attend, and what is the ruling on sitting in mixed-gender gatherings with a mahram present and without a mahram, and how can a father who has started to compromise his religious beliefs be advised?

Steadfastness in obedience to Allah is a blessing that necessitates gratitude through increasing acts of worship and avoiding sins. A Muslim should mix with people with insight, without compromising their religion, adhering to the words of the Messenger of Allah, peace and blessings be upon him: "Whoever seeks Allah’s pleasure through the displeasure of people, Allah will be pleased with him, and He will make the people pleased with him. And whoever seeks the pleasure of people through the displeasure of Allah, Allah will be displeased with him, and He will make the people displeased with him." It is necessary to adhere to the Sharia guidelines in family gatherings, and not to exceed them with unlawful mixing or immodest display. Advice should be offered to family members with wisdom and good admonition regarding Sharia violations, clarifying that non-participation stems from observing the Sharia guidelines. Patience, steadfastness, and adherence to the truth, along with educating and guiding people, are the best means to help them find guidance.