I have often heard the line “Only what’s done for Christ will last”, but only recently read the whole of the poem. Here is the whole of the oft-quoted poem by CT Studd:

“Two little lines I heard one day,
Traveling along life’s busy way;
Bringing conviction to my heart,
And from my mind would not depart;
Only one life, ’twill soon be past,
Only what’s done for Christ will last.Only What’s Done for Christ Will Last