because he knows that Jem has a good head on his shoulders and he knows that he is very wise and mature for his age.
Jem feels a mix of curiosity and intrigue when Atticus calls them to the balcony, wondering what important information his father has to share with them. He respects Atticus and trusts that whatever he has to say will be meaningful and insightful.
In "To Kill a Mockingbird," Jem shows admiration for his father Atticus's qualities like humility, integrity, and fairness. When he says he wouldn't care if Atticus had special talents, he is emphasizing that Atticus's character is more important to him than any external abilities or achievements. Jem values Atticus for who he is as a person, not for any special skills he may possess.
Its when Jem builds the snowman and replicates Mr Avery. Then Atticus says that to him. I think its because Jem has showed signs in the past that he wants to do what Atticus does; law, not sure about engineer and portrait painter as Jem has shown that he is artistic when he builds the snowman. Actually I think he says engineer as its something completely different from the other 2 jobs he mentions, which exaggerates the diversity of Jem's future.
Atticus says this because Jem and Scout trespassed and disrupted the peace at the Radley Place, which is a serious offense. He believes that they should respect others' property and privacy, regardless of their curiosity about Boo Radley.
Atticus says Scout should ignore Jem in the tree house because he wants her to give Jem some space to come down on his own without feeling pressured or embarrassed. He believes that Jem needs time to process what happened and make his own decision to come down.
Atticus tells Jem that he can shoot bluejays, but advises him to remember it's a sin to kill a mockingbird. He explains that mockingbirds are innocent creatures that only bring beauty and music to the world.
When Atticus continues to argue with the sheriff about protecting Jem, the sheriff yells '' God damn it, I'm not thinking of Jem.
Atticus explains to Jem that Tom Robinson has a very slim chance of being acquitted due to the racial prejudices in Maycomb. He wants Jem to understand that despite evidence showing Tom's innocence, the jury may still convict him because of their biases. Atticus emphasizes the importance of fighting for justice even when the odds are stacked against them.
Atticus, being a self centered character that does not like to boast, is trying to pass his characteristics to his young son, hoping that he will understand what Atticus is trying to say as he matures and grows up. Jem may now do as his father says because Jem would like Atticus to acknowledge that he has understood what his father is telling him, and that he may gain Atticus' respect for doing as his father says.
Miss Maudie responds by saying that Atticus is the same in his house as he is on his lawn, indicating that he stands by his beliefs regardless of public opinion. Atticus tells Jem that he doesn't believe in holding grudges, emphasizing forgiveness and understanding as important values.
Atticus says Jem would not talk about the courthouse because he was trying hard to forget something, but what he really was doing was storing it away for a while, until enough time passed. Then he would be able to think about it and sort things out. When he was able to think about it, Jem would be himself again.
At the beginning of the book Jem thinks Atticus is old and not very active. Ch. 10, p.99 "Jem was football crazy. Atticus was never too tired to play keep-away, but when Jem wanted to tackle him Atticus would say: 'I'm too old for that, son.'" Other people Jem knew had lots to say about their fathers who went hunting, playing poker or smoking. Yet, Atticus did none of these things. Even when Atticus gave Jem and Scout air rifles, he would not teach them to shoot. However, Atticus did give Jem one piece of advice 'Shoot all the bluejays you want, if you can hit 'em, but remember it's a sin to kill a mockingbird' (Ch.10, p.99). This phrase can be interpreted in a number of ways. Atticus could be referring to actual birds or he could be referring to Boo (Arthur) Radley as a mocking bird. Furthermore, as the storyline proceeds we, as well as Jem, learn that Atticus used to be 'the deadest shot in Maycomb County' (ch.10, p.108) as he shoots a mad dog. Atticus no longer uses a gun unless in an emergency as 'he realized that God had given him an unfair advantage over most living things' (ch.10, p.109). After this, Jem looked at Atticus differently. He thought of Atticus as a gentleman and learnt to respect him more. I think the mad dog incident is ironic as Atticus is protecting Maycomb Community from the mad dog, then later he is trying to protect Tom Robinson from the Maycomb community. In addition, the dog is called 'Tim Johnson' which is a name not unlike that of 'Tom Robinson' and the reader can see that Harper Lee is creating an analogy between the two events.