It was assembled in a particular order such as this...Actually, it's largely just been assembled in historical fashion. Obviously, the gospel accounts of Jesus and the Apostles flow historically into the ascension of Jesus into heaven in the book of Acts and the ministry of the Apostles. And then into the ministry of Paul.
Take a sinner to the gospels to give them something to believe in.
Then take the sinner to Acts 2:38 as they repent, so they can obtain remission of sins per water baptism in the name of Jesus Christ(and also become Spirit filled).
Then, as they qualified for sainthood, read them the Epistles which are letters written specifically to them as saved persons per Acts 2:38.
This is something you cannot learn in seminary, but they spend 8 years teaching it backwards(skipping Acts).