The PIE language gives us two roots for the word fire. *paewr- gives us our word 'fire' and means fire as in the act of combustion, fire as a substance. *egni- is the spirit of the fire, fire as a living energy. It is this root that gives us words like ignite. The god of fire is the Aryan-god Agni. His sacred sign is the swastika. He is wed to a goddess called Svaha, and many Hindu's believe that it is Svaha who gave her name to the Swastika - Svaha and astjih, with the suffix ka. In Saxon-Wodenist lore Angi is known as Ing or Inga (the name is a reflection). Ing or Ingwe is also known as Frey.
The sacred fire or sacred flame is symbolic of the spirit or soul of a person. This is the flame of being. Our sagas describe the first humans as a male and female called Ask and Embla. As in other Aryan mythology (such as Iran/Persia) they were carved from trees.
The gods bestowed various gifts of being unto them - such as sense, blood, thought etc. But Odin gave them spirit - which he blew into them. This 'spirit' was the flame of being. When he blew he ignited their flame of being. Ask and Embla is often translated as Ash and Elm (both trees) - but Ash and Embers would also be fitting - for these carry the potential for fire (life), which can be rekindled by blowing into them.