Roof radical at the top - a pictograph of a sloped house cover. It indexes 宗 in the dwelling-and-clan family alongside 家 home, 室 room, 安 peace, 守 to guard. The roof anchors a domestic ritual scene: under the family roof sits the altar.
Underneath sits 示 'altar', originally a pictograph of a stone slab where offerings were laid. Roof + altar = the room where ancestors are worshipped. From this concrete image grew every modern sense: ancestral clan (祖宗), school of thought (宗派), purpose (宗旨), religion (宗教). 宗 is a compound ideograph, not phonetic.
