be-all and end-all
1.PHRASE 短语唯一重要的事物；全部；根本 If something is the be-all and end-all to you, it is the only important thing in your life, or the only important feature of a particular activity.
【搭配模式】：v-link PHR
For some people, competing is the be-all and end-all of their running.
对于有些人来说，赛跑的全部意义就是竞争。
