Ruling on Muslims participating in other faiths' religious festivals

Answer

Peaceful coexistence and partaking in others' religious festivities are not mutually exclusive -- not participating does not mean not coexisting. Muslims may freely participate in every non-religious element of shared culture (language, food, folklore, social structures) without restriction, but religious cross-participation is different: bearing witness to the truth of Islam is not compatible with also witnessing the worship of other than Allah. Muslims lived in multi-religious societies since Madinah through the Umayyad, Abbasid, Andalusian, and Ottoman periods without a push toward participating in one another's religious rites as a condition of peaceful relations -- that expectation is new.