> Is Abraham a good father? In order to get a wife for his son, he sent his servant to go to his own relatives and asked his servant to not to get a local girl as his daughter-inlaw.
We don't know much about his fathering. He did seek out a non-Canaanite as wife for his son, which is a good thing, but he also let Sarah throw Ishmael out of the camp (Gn. 21.8-14), and Ish and his mom, Hagar, almost died in the wilderness. Without much else to go on, I would say he's not ideal, but we hardly know anything. Regardless, he's tough to preach a positive Father's Day sermon about!
> Which verses show that Lot is righteous? Is that because angels talked with him before?
2 Peter 2.7. We can talk about more if you want. Someone asked a few weeks ago specifically about Lot, and I wrote out a lengthy answer. But I don't want to just dump that on you. If you want it, you can ask for it, and I'll back up the dump truck.
> Although he's a sinner, he still could choose to teach his kids the right paths. But he did not. So his inaction made his sin more heinous.
Agreed.
> As for Amnon and Absalom, If they learned God's words carefully, this tragic story may not happen. God's words are crucial to our own life, because people around you are not always right.
Also agreed. Regardless of our upbringing and examples, we are all still responsible for our values and decisions. Everyone gets to set their own course (decisions, character) in the midst of the course that others set for us (upbringing, education, influences). Some people grow up in horrible situations and turn about fantastic; some grow up in fantastic situations and turn out horrible. Amnon and Absalom made their own choices.
> I don't recall anything about deceit. Can you explain a little more?
The whole setup to Amnon's murder is a deceit. First of all, Absalom was enraged and hated Amnon (2 Sam. 13.22), but he stayed quiet for two years. Revenge is juiciest when the victim is unsuspecting and unwatchful.
Then Absalom two years later casually invites all the king's sons to come for a feast. This is a conspiracy, for sure—a carefully planned strategy. When the ruse looks like it's going to fail (13.25), Absalom makes sure that Amnon at least comes (vv. 26-27). Knowing he has tricked Amnon into his grip, he orders his assassins to strike when the moment is ripe (v. 28). Verse 32 makes explicit Absalom's duplicity.