The six-pointed star is a very old symbol, not linked to any particular religion.
It is helpful to think of it as composed of two triangles. One points upward, and symbolises all our hopes and aspirations.
The other points downward, and symbolises the light that comes to us, like grace from heaven.
The two triangles completely joined with no divisions, symbolize perfect balance. It means balance between the gifts of life and our gift to life.