[size=150]φιλοῦσιν[/size] and ἀποθνῄσκει are verbs, so ὃν οἱ θεοὶ φιλοῦσιν means roughly:
“The gods love the one who…”
and the rest means
“…dies young.”
(I think it means that he dies young because the gods love him, rather than the gods love him because he dies young. But I’m not certain. Perhaps someone with more Greek knowledge than I have is needed to say for sure.)