I am not much of a guy for poetry, but this sticks with me.
In latin (which I do not read) it seems to have an even heavier feeling.
Vita brevis breviter in brevi finietur,
Mors venit velociter quae neminem veretur,
Omnia mors perimit et nulli miseretur.
Ad mortem festinamus peccare desistamus.
A rough english translation
Life is short, and shortly it will end;
Death comes quickly and respects no one,
Death destroys everything and takes pity on no one.
To death we are hastening, let us refrain from sinning.