In the depths it is lonely

Even with fans and family, deep inside he feels lonely, like a shark in the depths of the sea.

The fire keeps you warm

The love they got for music keeps them alive.

Six hearts that burn

there are six members in Rammstein

Their passion for music burns inside, it needs to go out.

We hold each other by the arm

Similar to we stick together

We keep our eyes open

Sharks don’t have eyelids.
A metaphor to express that living the “artist life” doesn’t get you much sleep (touring, compose, etc.). .

Also, “die Augen offen halten” is a synonym for “to pay attention”. The band pays attention to themselves (and maybe to the fans and current developments around the world as well).

And the shark, it has tears
And they run down his face

Shark are misunderstood creatures that frigthens most humans. Most humans think of sharks as an evil, emotionless, bloodthirsty animal. Rammstein don’t really have a good reputation either, they are mostly shown as a evil band (Example).

Till point out that sometimes what you see isn’t what it really is. Sharks, just like Rammstein, isn’t evil; what you see is just a facade.

This is also a homage to “Das Moritat von Mackie Messer” ( also known as “The Ballad of Mack the Knife”), a song from the the musical stage play “Dreigroschenoper” (“Threepenny Opera”), by famous German dramatist Bertolt Brecht. The play premiered in August 1928 in Berlin.

Original lyrics:

Und der Haifisch, der hat Zähne
und die trägt er im Gesicht
und Macheath, der hat ein Messer
doch das Messer sieht man nicht.

And the shark, it has teeth,
And it wears them in its face.
And Macheath, he has a knife,
But the knife one doesn’t see.

Also the connection with Bertolt Brecht is something that’s that could be interpreted as an allusion to their political stance and their denountiation of their connection with fascism and nazism (as is http://rock.rapgenius.com/Rammstein-links-2-3-4-lyrics which is also an homage to another Brecht song: http://poetry.rapgenius.com/Bertolt-brecht-einheitsfrontlied-annotated).

No one will slow us down

No one will prevent them from making music. A lot of their videos created controversy; (Pussy, Mann gegen mann and Mein Teil)

A reference to people who refer them as an evil band (Some even think they are nazis…)

We stick together

Since their formation in 1994, Rammstein has had no changes in their band line-up nor have any members left the band.

We hold together
We put up with each other

Like a bunch of sharks, the band stick together since 1994.