The first obvious sign of being placed within the Jewish faith as a male infant is to have inflicted upon oneself an act of genital mutilation. Personally, were I in said situation and of sufficient intellectual development as to defend my person in word if not in deed, I think I would choose to have my body unmutilated and remain a spiritual free-agent, so to speak.
I would, it is claimed however, receive the punishment of Kareit, which means "excision", by which one loses one's spiritual connection with the divine source. The blood sacrifice creates a spiritual pathway to God.
Why would God require the sacrificial bond of infants' blood? Is this how he recognises his chosen people? Like a cattle brand. Also trying to place myself in the position of the perpetrator of the act: inflicting quite a grievous and bloody injury upon an eight day old infant seems an action I might consider on the barbaric side of things.