The Christian religion is present in each of the 28 panels but most focus exclusively on the life of Jesus Christ, as seen in well known episodes such as his birth, baptism, crucifixion and eventual resurrection. Ghiberti then uses other key figures to complete the series after the main themes of Christ are covered.
Saint Luke here is depicted sat at his desk, surrounded by just a small collection of items. Luke was one of the Four Evangelists, according to Christian scripture and artist Ghiberti chose to include each of them in his final panels, see also Mark, Matthew and John.
It is generally accepted that Luke himself was a Greek physician from Ancient Syria. His religious affiliation was actually as a Hellenic Jew. Different passages from this period, and since, have given slightly different accounts to his life and personal characteristics, though most accept that he was, at some point, a disciple of the apostle Paul up until Paul's death.
To understand more about the different ways in which this saint has been depicted over the centuries by a mixture of artists, it is worth studying some of his more famous portraits, such as James Tissot's Saint Luke and a further work by Maarten van Heemskerck. One pleasing element to Ghiberti's work is that more gilt remains on it than almost any other from this series.