Sigils are representations taking the form of unique symbols, of elements in magical practices. They may represent Angels, Demons, Spirits, Djinn or even humans and even thoughts and actions. More on this can be found on the Sigils Magick page.
Angels are the creation of light and not any ordinary light, in Islamic and christian scriptures Angels are said to be the first of God’s creation and they were created from light which is the light of God himself (that which also forms God), it is described as ‘Noor’ in Islam, a glowing, soothing, warming light that fights away darkness.
There are thought to be legions of Angels most of whom are for eternity praising their (and our) creator God. But there are some notable Angels who have specific roles and known names, these are even considered to be the higher ranking or more powerful Angels. Since names of these Angels are known, Sigils or Symbols representing them have formed which can be used to summon, communicate with or even control these Angels.
The problem lies with finding or creating Sigils that are powerful and effective enough, as there are some discrepancies regarding the real names of these Angels and even the techniques to create Sigils have also become varied with time.
In my quests I have found that time has been used like an illusion, with the passage of time the names of Angels were pronounced and spelled differently and more basic forms of knowledge the knowledge of numbers became lost or altered, hence Sigil creation techniques were also altered.
That is why finding ancient Sigils is useful as they are probably going to be more powerful, but whats even better is to find out what has been lost and to look beyond the illusions time has created, only then can one truly perform powerful magic.