The answer is not hard. Just a missing word in the space at the end.
In the end, it's what kills you.
But before, it's what fills you.
Picks you up, and lets you down.
Fills your cup, and makes you drown.
It will teach, and make you sound,
Plant your feet on solid ground.
Ever to and fro it goes,
Leaping deer, and little does.
Where you plant and farm hand hoes,
Starts to move around your toes.
It will pull, and it will tear,
It will hurt, and it will wear,
It's not easy, it's not fair.
But you'll make it if you dare.
And it grows in summer beams.
And it flows in winter streams.
Oh, it glows in honey gleams,
And it shows, in time redeems.
It is beauty, and it's strife.
But it's love, and yes, it's ____.