I always figured it was about Dahlia, and life in general, from Alessa's point of view;
"the love you never gave
I give to you"
Referring to the fact that Alessa just wanted a normal life with her mum, and not to be the blasphemous holy mother.
"So insignificant
sleeping dormant deep inside of me"
And
"so many seeds have been sown in the field
and who could sprout up so blessedly
if I had died "
The god.
"if I had died
I would have never felt sad at all"
She just wanted to die.
"you will not hear me say I'm sorry"
After the burning, she was consumed by hatred for all things, her mother in particular.
"where is the light"
She's trapped in the otherworld.
"wonder if it's weeping somewhere"
She takes pure, unhinged despair to another level.
I always figured it was about Dahlia, and life in general, from Alessa's point of view;
"the love you never gave I give to you"
Referring to the fact that Alessa just wanted a normal life with her mum, and not to be the blasphemous holy mother.
"So insignificant sleeping dormant deep inside of me" And "so many seeds have been sown in the field and who could sprout up so blessedly if I had died "
The god.
"if I had died I would have never felt sad at all"
She just wanted to die.
"you will not hear me say I'm sorry"
After the burning, she was consumed by hatred for all things, her mother in particular.
"where is the light"
She's trapped in the otherworld.
"wonder if it's weeping somewhere"
She takes pure, unhinged despair to another level.
It's just my interpretation though.