The equilateral triangle is a symbol of the Holy Trinity. God the Father, God the Son and God the Holy Ghost are no longer represented in human form, or as a dove, but by this geometrical figure. This ‘God-Logo’ can be used in many places: on altars, on church ceilings, above the entrance or on tombstones. It is often surrounded by a halo of rays of light of godly magnificence. It announces: God is here. Where the triangle is painted, it is usually in gold, sometimes in blue. Both colours embody Heaven.
Within t
he triangle, the Eye of God can usually be seen. He looks graciously down at the people and makes His face to shine upon us, as it says in the Aaronic blessing. The idea that nothing is hidden from the Eye of God leads to that of insight into human sinfulness and thereby to confession – which played an important role in those days.
If the Hebrew name for God ‘Jahwe’ is also in the triangle, it is a 
reminder that God revealed Himself to Moses in the burning bush. That spot in the desert became a holy place, just as the church is a holy place. When translated, the word for God also means ‘I am with you’ – just as Jesus promised at His Ascension to Heaven.
Tongues
of fire within the triangle may express God’s holiness: ‘dwelling in light unapproachable’ . His Majesty is like a burning fire, like the sun. Three tongues of fire refer to Whitsun, when the Holy Spirit came down like tongues of fire upon the disciples. In St John’s Gospel , Jesus says: God is spirit, and those who worship Him must worship in spirit and truth. The place and the building are irrelevant.
The triangle and light symbolism also feature in freemasonry, and Margrave Friedrich founded the freemasons’ lodge in Bayreuth. However, the triangle as a sign of God is older and much more widespread, and the same is true within the realm of the catholic church too.