Ah so you are saying that a core belief, that is sacred to the individual, would not be abandoned even under the threat of death ? that i can understand and accept, however i have yet to meet one with a set of beliefs that they would die for.
I would suggest you explore Eastern religions. Not for a belief in God, but for an understanding of belief systems. At fifteen, you're already very wise in many ways, it may help you to cope with the stressors of life.