These are the lyrics we have in the Rise Up Singing Songbook. They're a composite of the popular recordings of this song.

LET'S GET TOGETHER
(Chet Powers)

Love is but a song we sing
Fear's the way we die
You can make the mountains ring
Or make the angels cry
Though the bird is on the wing
And you may not know why

C'mon people now,
Smile on your brother
Everybody get together
Try to love one another, right now!

Some will come and some will go,
We shall surely pass
When the one that left us here,
Returns for us at last
We are but a moment's sunlight,
Fading in the grass
(CHORUS)

If you hear the song I sing,
You will understand
You hold the key to love and fear
In your trembling hand
Just one key unlocks them both,
It's there at your command
(CHORUS)


Notes from the Wikipedia article:

"Get Together", also known as "Let's Get Together", is a song by American rock band The Youngbloods, originally included in their 1967 self-titled debut album The Youngbloods. It was written in the mid-1960s by American singer-songwriter Chet Powers (stage name Dino Valenti), from psychedelic rock band Quicksilver Messenger Service. The single was The Youngbloods' only Top 40 on Billboard Hot 100—peaking at number five in 1969.