Why does Galatians come after Romans in the New Testament when it was written first?

Galatians follows Romans in the New Testament because Romans is the doctrinal book. Though Galatians was written earlier, the Holy Spirit placed Romans where it belongs, since all Scripture is profitable first for doctrine; Galatians serves correction, addressing legalism and bringing believers back on course.

Les explains that Romans is the doctrinal Book, so even though Galatians was written earlier, the Holy Spirit puts Romans in the New Testament exactly where it belongs. All Scripture is given and profitable first of all for doctrine. The next two books, the Corinthian letters, fit reproof because the church had immorality, dissension, divisions, legal disputes, and disputes over foods. Then comes Galatians, which though earliest is fourth in the order of the Church letters—written before Romans but after in New Testament order—because it was written for correction. The Galatians were slipping into legalism, and the book was written literally to bring them back on course.

Where does Galatians fit in the order of the Church letters even though it was written first?

Galatians stands fourth in the New Testament order of the Church letters, even though it was written before Romans. Romans is placed first for doctrine, the Corinthian letters follow for reproof, and Galatians comes fourth for correction, addressing legalism and bringing believers back on course.