In the first episodes of Season 4, Chloe tries to determine if Lucifer is a good person/friend or the villain he has been made out to be by the church. Father Kinley tells her that Lucifer only thinks of himself and manipulates people into thinking he is good. Lucifer's intentions, according to Father Kinley, are only about getting what he wants.
Although Lucifer is self-centered and can be narcissistic, his grand gestures do prove that he cares about others. Still, we have moments where Lucifer is oblivious to what others are going through, and doesn't seem to care about their struggles.
Good Friend: Saves Chloe
Lucifer saves Chloe multiple times. Although Chloe is his romantic interest, they do start as friends. He respects her and admires her ability as a detective. In addition, she challenges him, which allows him to grow. After Lucifer learns of his vulnerability when he is around Chloe (that he can be injured when she is near), he still continues to put himself in harm's way to protect her.
One moment is in Season 4, Episode 2, Lucifer jumps in front of the ax that was meant for Chloe. Luckily, nothing but his suit is harmed. Chloe asks him why he would risk himself, knowing that he could be killed. He replies sincerely, "And I would do it again. And again. Don't you know that, Detective?" It is a moment where Lucifer's normal light banter fades, showing his sincere and unselfish side.
Bad Friend: Doesn't Care About Amenadiel's Wings
Lucifer's big brother, Amenadiel, suffers an incredible loss to his identity: his wings and powers. All throughout Season 2 and 3, we can see how little Lucifer cares about Amenadiel's loss of identity and purpose. Amenadiel finally gains a small sense of purpose, discovering that he is dear Dad's favorite, in Season 2.
Immediately after discovering that welcome piece of news, Amenadiel hesitates to give Lucifer a needed tool to fight against their mother. Lucifer replies, "Don't make me hurt you. Remember you're not the angel you once were." Here he rubs Amenadiel's face in the loss of his wings and powers. It seems that he takes joy in both bringing his brother down a notch and in hurting him.
Good Friend: Welcomes Eve
Upon discovering the return of Eve in Season 4, he welcomes her to Los Angeles and assures her safety. Initially, she isn't welcomed into his house, as she had hoped, but he sends her off to stay in a hotel. When the "Uber" driver tries to hurt her in order to retrieve a necklace that Eve doesn't actually have, Lucifer moves to protect her. The rest of the episode is Lucifer trying to recover the necklace so that Eve can be safe.
Bad Friend: Breaks up with Eve in the Worst Way
Now, it can be said that Lucifer did try to break up with her in an amicable way. Then he tries to have Eve break up with him. Neither of these work. So, he tells her that he doesn't like who he is around her. While this may be true, this statement is pretty hurtful to Eve.
He seems to forget that Eve came here for him, that she sees him as someone who accepts her. By saying this, it comes across that he doesn't accept her. Eve, following old patterns, tries to change to accommodate him. New to Earth, Eve needs a little more sympathy than she got.
Good Friend: Helps Amenadiel Get Justice
Caleb, a high school student Amenadiel helps out, gets killed by a drug dealer. Worried about being a father, Amenadiel had practiced on Caleb in Season 4 Episode 8. He got Caleb out of a sticky situation (Caleb was being forced to sell drugs), and he even bought him ice cream. Caleb assured Amenadiel that Amenadiel will be a great father. Then, all hell breaks loose. With Caleb dead, Amenadiel wants justice.
He says to Lucifer once Chloe is out of earshot, "I know who did this." Lucifer immediately responds, "I'll drive." Once they get there, Lucifer keeps the others at bay so that Amenadiel can have his one-on-one with the dealer. In the past, Lucifer hasn't read situations well. This time he leaves his own issues and helps his brother.
Bad Friend: Disregards Maze's feelings
It takes Linda making Lucifer sit down with her and Maze in Season 2 for Lucifer to realize that Maze has felt abandoned by him. We would think that this would change, but in Season 3 he also doesn't think of Maze's feelings.
He doesn't understand that she wants to return to hell. Because he doesn't want to go, then she isn't to go back. Later, Maze admits to liking Earth, but at this point she misses home. Maze is loyal to Lucifer, but he takes that loyalty for granted.
Good Friend: Gives Mom her own world
Lucifer has a bad relationship with both of his parents. He complains to Linda that his mom watched while dear Dad pushed him out of heaven, doing nothing. This is why when Dad did the same to Mom, Lucifer also did nothing. Mom was tortured in Hell, and Lucifer (holding grudges) did little to reach out to her. In Season 2, we are teased with the idea that Lucifer is going to kill Mom with the Blade.
Instead, he uses the Blade to create another world where Mom can live free of dear Dad. He gives her freedom. And she, in return, gives us Charlotte back. At this point, we don't know Charlotte since she was dead before Mom inhabited her body. Charlotte will come to be a very important character for the main characters. Linda and Amenadiel will even name their child, Charlie, after Charlotte.
Bad Friend: Disregard for Linda's Time and Feelings
All throughout each season, Lucifer expects Linda to come when he calls. He disrespects her work with other clients, saying that his problems are more important. He sees Linda as someone who is strong and who will bounce back, all of which she is, but he doesn't take into full account her feelings. For instance, she was severely hurt by his mother, and Maze seems to care more about this than he does. Also, when he learns that she is pregnant, he tells her a quick congratulations and then moves on to more important things, himself.
However, it can also be said that he allows Linda in more than others, partly because she is his therapist and partly due to their friendship. When he discovers that his bat wings have come back, she is the one that he calls. Allowing a friend to see him in this state speaks to a high level of trust and friendship. Still, it is a friendship where Lucifer takes more than he gives.
Bad Friend: Makes Fun of Dan
It is not clear if Lucifer even considers Dan a friend. He frequently calls Dan, Dan-the-douche. He insults Dan any chance that he can get, but as Dan as a member of the group, he is a friend by association.
In Season 3, Bonus Episode 25, he buys pictures of a terrified Dan on a roller coaster, "200 for $200." He puts the picture on T-shirts and hats. Lucifer plans to share this to all at the precinct. Constantly undermining Dan's authority and credibility, it is easy to see why Dan is so frustrated with Lucifer, even if Season 4 proves Dan to be even more of a 'douche.'
Good Friend: The Ultimate Sacrifice
Lucifer has been fighting against returning to hell since Season 1. However, in Season 4, when he sees that the demons are going to continue to come to Earth to hurt those he loves like Charlie (he cares for Amenadiel and Linda's baby!) and Chloe, he knows that he needs to go back. He is not going back because he wants to; he is going back to protect others.
Saying good-bye to Chloe, his angel wings are back, as he readies to travel back to hell. We see him on the throne, lonely and unhappy, but remaining there for the greater good. When he was made the King of Hell by Dear Dad, he was forced to play a role. Now, he chooses to play the role in order not to lose those he loves. This sacrifice proves a great character arc, and we are excited to see what happens next season.