Eli's ruin is that he loved his sons more than the order his office was sworn to serve. The priests are meant to guard the sacrifice, the thin channel between a people and what stands above them. Instead they fatten themselves on the best of it and call it their due. A father who will not correct his corrupt sons has quietly chosen them over the truth. He honors the near thing above the highest thing, and the whole structure rots from the middle.
Every man carries a hierarchy of loves inside him. What sits at the top decides everything. Put appetite and blood above the sacred, and you begin devouring what you were trusted to protect. Guard what is handed into your keeping, or it destroys you through the very people you spared.