The Core message of the Bible:
1 John 4:8
1 John 1:5
For our certainty, Luke makes us able to see the depths of betrayal - why?
So that we'd know Jesus obedience and perfection, yes.
So that we'd know God’s perfection and love for us, yes.
But more than that, so that we'd see the thread of betrayal that runs through us, and as an undertow of all humanity.
: to give information about (a person, group, country, etched.) to an enemy
: to hurt (someone who trust you, such as a friend or relative) by not giving help or by doing something morally wrong
2 Corinthians 4
This is the root of betrayal in us:
2 Corinthians 4:6