Sunday is represented by the Blue Flame which possesses cristal-clear radiation. This ray carries the Light of Knowledge as well as the energy of the Divine qualities of Faith, Strength, Power, Protection, and Sweet God's Will.
Invocation for Sunday
"Beloved Presence of God, I AM in my heart, I love Thee and adore Thee. I invoke THY BLUE FLAME to blaze through me, making only Thy Sweet Will manifest in everything I do. I am aware that within me there is a Divine Plan for myself together with the possibilities and ways for it to be manifested externally.
I Am Faith in the almightiness of God which is ruling me, protecting me, enlightening me, healing me, supplying me, supporting me and doing everything that should be ever done for myself. All that uplifts and connects, that liberates and leads the consciousness to God is good, it is God's Sweet Will. I do not need any occult exercises or outside councilors, the life which moves my heart knows what is good.
Everything that gives release and liberation from shackles, is Divine."
Note: This is only a shortened version of the Sunday Invocation!
You can also directly invoke the help of Archangel Michael and Elohim Hercules, who are responsible for the energies of the Blue flame and for the First light ray in general.
Yellow Flame Invocation