Triad 

Triads is the plural of Triad.

In the ancient mythologies there were Triads, which consisted of a mysterious union of Three Deities.   Each triad seemed to consist of a creator, a preserver, and a destroyer.

Christianity, just like the older so-called Pagan Religions, has established a Triad which consists of the Father, the Son, and the Holy Ghost.

Christianity has adopted, or somewhat modified, the beliefs of many of the ancient Sun Worshipers whom Christians now consider as pagans.