When it comes to the various members of the Avengers in the MCU, each of the heroes has proven themselves as brave. They have all been willing to make huge sacrifices in order to save the day. However, that bravery comes more easily to some than it does to others.
There are some of the Avengers who are perhaps new to the superhero game and are sometimes daunted by the challenges they face. Then there are heroes who were ready to rush into battle and put themselves in danger long before they became superheroes.
Ant-Man
Scott Lang aka Ant-Man is one of the more ordinary of the Avengers. He is a family man and former good-hearted criminal who finds himself becoming a superhero. And part of the charm of the family-friendly Ant-Man movies is that he often seems in way over his head.
He is shown to be understandably panicky and scared during his initial training with the ants. And even when he joins the Avengers, he is the member of the team who seems the least sure of himself.
Spider-Man
Given that Peter Parker aka Spider-Man is the youngest member of the Avengers, it makes sense that he is also not totally comfortable as a hero yet. He always gives it his best effort, but it takes a bit more to summon his courage than it does for other heroes.
He is shown to be afraid of heights, even though he can swing from tall buildings. He also fears for his life at times, such as when he is covered in rubble by Vulture or when he is unsure of what's real after Mysterio's mind games. But in the end, he is always able to overcome his fear.
Doctor Strange
Given the kind of interdimensional threats he faces and the horror elements of his world, Doctor Strange would probably need to have a lot of courage for his job. While that comes with time, he is another very hesitant hero when he first begins his journey.
Though Strange was a brilliant surgeon, once he is introduced to the world of sorcerers, he begins to think it is too much for him to handle. At one point, when confronted with the evil he must battle, he even tries to quit only to later realize how much he is needed as a sorcerer.
Scarlet Witch
Wanda Maximoff aka Scarlet Witch is one of the most powerful heroes in the MCU and sometimes it seems like she is afraid of her own power. She often has to face the consequences of her actions and the fear of seeing what she is capable of.
Wanda's emotional journey in WandaVision also sees her fearing for the new reality and family that she made. When that happiness is threatened, she becomes fearful that she will lose everything and that causes her to act in questionable ways.
Thor
Thor is likely the most arrogant of the Avengers, so it would make sense if he was also the bravest. And while Thor is fearless when rushing into battle most of the time, his bravery is tied directly to his power so once that is gone, he becomes a lot more nervous.
This can best be seen in Thor: Ragnarok when he loses his hammer and believes he has lost his power. From screaming like a child when meeting the Grandmaster to his faceoff with Hulk, Thor lets his fear show for the first time.
Iron Man
As the first hero of the MCU, Tony Stark aka Iron Man very much set the standard for the Avengers who followed. But in his first scene, he didn't establish himself as a fearless hero but rather someone who was terrified of being in a dangerous situation.
Throughout his time in the MCU, Tony is someone who never ran from a fight but was also not thrilled to be fighting in the first place. From his initial capture to the aftermath of The Avengers to heading into space, Tony always reminds audiences that he is just a man underneath the armor suit.
Black Widow
Along with Hawkeye, Natasha Romanoff aka Black Widow seemed out of her league as a member of the original Avengers at first. But she soon proves herself a valuable member of the team.
She brings a certain humanity to the group of extraordinary heroes, showing that she can be shaken, such as her encounter with Hulk. But she will always shake it off and get back in the fight. She is even willing to make the ultimate sacrifice to save the day in Avengers: Endgame.
Captain Marvel
An interesting aspect of Captain Marvel's origin story is that her true power is being suppressed by those around her. However, even if she isn't aware of just how powerful she is, Carol Danvers always acts as if there was no threat she can not face.
It is shown that, even as a little girl living on Earth, Carol can pick herself up after getting knocked down. She is constantly underestimated by those in power but always has the bravery to prove them wrong.
Black Panther
T'Challa aka Black Panther has obviously shown bravery on the battlefield, such as leading the attack on Thanos's army. But it is his bravery as a king that is even more impressive and inspiring.
T'Challa is able to admit he is unsure of becoming king but proves he is the right man for the job. When T'Challa is proven wrong, he addresses his mistakes and works to make things right. In fact, his decision to open Wakanda to the rest of the world is one of the bravest actions performed in the MCU.
Captain America
Steve Rogers aka Captain America is the best example of someone who showed the bravery of a hero before they were a superhero. As a skinny young man, Steve was always willing to stand up to bullies, even if he knew he couldn't win the fight.
As Captain America, that heroic spirit only grew as he acted selflessly to protect innocent people and save the day no matter what. He would never stay down and was always ready to face unbeatable odds if there was a chance he could save the day.