Raziel is the patron of all Shadowhunters and the creator of all Nephilim. As it is written the Angel Raziel rose form Lake Lynn, bearing with him the Mortal Instruments. On the banks of the lake Raziel placed the Cup, the Sword and the Gray book. With his finger he gently inscribed across the wounded Jonothan's arm the first Iratze seen on Earth. Then Raziel lifted the Cup and in it mixed his angelic blood and the blood of Jonathan and said:

"In your dream you saw a great truth, that to destroy the things of darkness, it is sometimes necessary to decend into the shadows of join them. You shall bring men and women into the darkness with you, and you will master the shadows, and you will hunt. From now unil the end fo the world, you shall be called Jonathan Shadowhunter, for you and your kin will drive the shadows of the world away. And you will make light in dark places. And you will be called Nephilim, as it says in the book of Genesis. "The Nephilim were in the earth in those days, and also after that, when the sons of God came unot the daughters of men, and they bare children to them: the same were the mighty men that were of old, the men of renown." for you will be of men and yet you will be of Angels; both in one." 

We can not say much about the Origin of demons. All we can say for sure is that they were in our world well before humans came to be. In the beggining was the world, and light and humanity and goodness, but there was also demons. Sammael and Lilith, mother and father of all evil to come, the paragons of corruption and sin. They mated with humans and created warlocks. Their kind mated with Angel's who in those times would be found on Earth and created fairies. At some time around the very beginnings of humanity, the demons grew too strong and too many, Heaven declared war on them. Heaven won the war although the Angel's were unable to eradicate the demons from the world. Nephilim folklore tells us that this war between Heaven and the demons decimated Earth. Time passed. Stability came to Earth and human history as we know it began.

The Angel Raziel in his generoisty had two more gifts for Jonothan. 

The first was the gift of adamas the heavenly crystal that glowed with heavenly fire that could not be cut or carved by mundane means, and the secrets of whose workings could only be found in the Gray book. He then presented a branch of polished adamas to Jonothan which was the first Stele. 

Then Raziel raised his hands and from the ground came spires of towers many times the height of a man, spiked and yearning toward the sky. From many places on the plain came and when they had all grown Raziel led these first Nephilim to a spot in the midst of the towers where four smaller towers stood describing a diamon and there he gave them the second gift. The gift of Idris.

"This shall be your country. A haven for all the Nephilim and those who beat against the shadows of this world." 

Before Raziel left Jonathan at Lake Lynn he said one final thing: "If you again find yourself in true need- true need of me, take the Cup, the Sword, the Mirror- these Mortal Instruments- and summon me by the shores of this Lake" and with that he departed.