Why are Romans and the Corinthian letters placed before books that were written earlier?

Les explains that even though Romans and the Corinthian letters were written later, the Holy Spirit placed them up front because Paul first declares the basic doctrines of his Gospel in Romans. Then in the Corinthian letters he had to correct and reprove them for many problems—not legalism like the Galatians, but divisions. Some said they followed Peter, others Christ in His earthly ministry, some Apollos, and some Paul. In correcting these things, Paul also had to defend his apostleship. Les also stresses that if people cannot get back to an understanding of Paul's doctrines, Christianity is in dire straits.