These three circles...

form a kind of wall,within which you are secure from any "aggression",  from the spirit world. During the  invocation,you shouldn't step out of this "secure space"  before having completing the return of  the invoked Angel. Such a misadventure always has annoying consequences. The magical circle is not only an object of protection against the invoked forces. One could even say that it would be a shame and even dangerous to limit its use merely to this. Actually, the magic circle is a schematic representation of the world in which we live, the microcosm. As such, it is thus necessary to replace all the symbols of life: the four Elements symbolized by the cardinal points, the seasons, the names of the divinities that we respect and in which we believe and also the names of the summoned Angels or entities ... All these signs are placed in a specific order and direction, respectful towards the hierarchy.  All these elements together sign the effectiveness of the magic circle.