What is the ruling on a shaykh and Muslim officials attending a fundraising dinner organized by the Arab Christian community to purchase a church, and the shaykh delivering a speech at this dinner? And is it permissible to donate to them?

A Muslim's participation in building a church, whether by labor or donation, is impermissible because it constitutes cooperation in falsehood. However, merely attending a gathering where donations are collected for building a church is permissible if there is a benefit in attending, or if it repels harm from Muslims. Sometimes, their participation may even be recommended or obligatory if it serves a religious benefit, such as inviting them to the religion or averting their harm from Muslims.