The Hobbit, or, There and Back Again
How we cite our quotes:
The roar of [Beorn's] voice was like drums and guns; and he tossed wolves and goblins from his path like straws and feathers. He fell upon their rear, and broke like a clap of thunder through the ring. [...] [H]is wrath was redoubled, so that nothing could withstand him, and no weapon seemed to bite upon him. He scattered the [goblin] bodyguard, and pulled down Bolg himself and crushed him. (18.23-4)
Beorn basically seems like a one-man army: "nothing could withstand him, and no weapon seemed to bit upon him." Beorn is so overwhelming that it's almost as though he has nothing to fear. Given that Bilbo is so vulnerable and unskilled, we think it may have taken Bilbo more courage to face Gollum than it takes Beorn to scatter "the [goblin] bodyguard, and [pull] down Bolg himself."