Help me translate this word

치르게 될

chileuge doel

can someone help me translate that? google translate is giving me 'to be paid' but i dont get the exact vibe of the word. or rather the contexts it can be used in

the original sentence is

한시도 떨어지고싶지 않은 아내였지만 그는 두 달 후면 치르게 될 과거를 준비하느라 복륭사에 가있는 참이었다.

and its giving me a headache trying to understand what it means