英语翻译Her father told the captors that sparing her life would

英语翻译
Her father told the captors that sparing her life would serve your cause more than her death.
就是句子后面引号部分的意思,不太明白

spare one's time 节省某人的时间
spare one's life 这里理解为放过某人,饶某人一命
整句译为：
她父亲对那个劫持者说饶她一命比让她死了对你更有帮助.
P.S.因为没有前后文,很难正确翻译这里的captor和“serve one's cause”的正确意思.后者还可以理解为“帮助某人的事业”“实现某人的目标”