Attending the funeral of a non-Muslim relative in the church

Islam is the Deen which Alaah has sent Mohammed (Salla Allaah Aleihi Wasallam)
with; Allaah made it the last of religions and perfected it for His creation; He made it a completion of His Favors upon them, and chose it to be their Deen; No other religion is accepted from any one except the Deen ...

The Shahadah: the first Pillar of Islam (Declaration of the Islamic Faith):

However, the most important and fundamental principle of truth in Islam and all religions is the First Pillar of Islam as embodied in the Belief and Confession of Islam. This needs further clarification as ...