《鋼鐵是怎樣煉成的》中有壹句名人名言，應該如何翻譯成英文比較恰當？

The most expensive in humans - this is life. It gives him the once, and it must be to live in such a way that was not painfully hurt for aimlessly lived years in order not to disgrace zheg for podlenkoe and mercantile past and that, dying, has been able to say: the whole life and all forces were given the most beautiful in the world - the struggle for the liberation of humanity. "

Man's dearest possession is life. It is given to him but once, and he must live it so as to feel no torturing regrets for wasted years, never know the burning shame of a mean and petty past; so live that, dying, he might say: all my life, all my strength were given to the finest cause in all the world——the fight for the Liberation of Mankind.

--Ostrovsky

完整的這段是：

人最寶貴的是生命。生命每個人只有壹次。人的壹生應當這樣度過：回憶往事，他不會因為虛度年華而悔恨，也不會因為生活庸俗而羞愧；臨死的時候，他能夠說：我的整個生命和全部精力，都獻給了世界上最壯麗的事業——為解放全人類而鬥爭。

--奧斯特洛夫斯基