There are many different wordings that may be used in Consecrating and Blessing a Circle. They may vary from one Grimoire to another. It can be simple or complicated depending on your preferences. It can be long or short and worded to fit your needs.... it does not have to be from a Grimoire... it can be one that you have made up yourself and comes from the Heart. I myself prefer one that fits in with High Magic and God Almighty, such as the one below. What you are doing is simply Praying or asking the Deities that you believe in to Bless your circle and Consecrate it as your protection barrier. This one that I have provided here, is my favorite and it is from a book called "The Magus" a Complete System of Occult Philosophy.
Let me remind you that Casting a Circle is not the same. Similar in some ways but not the same. Casting a Circle is Ritual for Witches who want to set up a circle for protection and it is not the same type of circle as the ones on my Magic circle page.In the name of the Holy, Blessed, and Glorious Trinity, proceed we to our work in these mysteries to accomplish that which we desire; we therefore, in the names aforesaid, consecrate this piece of ground for our defense, so that no spirit whatsoever shall be able to break these boundaries, neither be able to cause injury nor detriment to any of us here assembled: but that they may be compelled to stand before this Circle, and answer truly our demands, so far as it pleaseth Him who liveth for ever and ever; and who says, I am the Alpha and Omega, the Beginning and the End, which is, and which was and which is to come, the Almighty; I am the First and the Last, who am living and was dead; and behold I live for ever and ever; and I have the keys of Death and Hell. Bless O Lord! this creature of earth wherein we stand; confirm O God! Thy strength in us, so that neither the adversary nor any evil thing may cause us to fail, through the merits of Jesus Christ. Amen.