惟有

The ancient people who was successful, not only had exceptional talent but also had unflinching will.

古人立大事者，惟有超世才，亦必有望忍志。

Only such a striver is valuable.

惟有这样的奋斗者才是富有价值的。

But inapt as I am, will follow your advice and perform my duties to the best of my powers.

虽才如，当谨如尊谕，力所能及者惟有勉尽天职也。