Told my son that my great aunt-in-law passed away. My son told me he felt sad even though he doesn't know her or seen her before.

One thing leads to another and we ended talking about death.

Son (S): When people die, they go to heaven?
Father (F): It depend. If they have Jesus in their hearts, they go heaven.
S: Angel comes to bring them to heaven?
F: Yes.
S: Why angel can fly? Is it because they have wings?
F: Yes.
S: Why angel has wings?
F: They are special God's messager.
S: How people have Jesus in their hearts?
F: When they pray and ask Jesus to go into their hearts. Just like what you did last time.

1 hour later, on his bed.
S: I cannot sleep.
F: Why?
S: I got so many things to think. Angel, Jesus and many things to think about.

I think my son can be a philosopher or theologian in the future. He is starting to ask existential questions.