The Sunday before the Nativity of the Lord (December 18-24) is known as the Sunday of the Holy Fathers. On this day the Church commemorates all those who were well-pleasing to God from all ages, from Adam to Saint Joseph the Betrothed of the Most Holy Theotokos, those who are mentioned in the geneology of Luke 3:23-38. The holy prophets and prophetesses are also remembered today, especially the Prophet Daniel and the three holy youths (December 17).
The Troparion to the Prophet Daniel and the three holy youths (“Great are the accomplishments of faith...) is quite similar to the Troparion for Saint Theodore the Recruit (February 17, and the first Saturday of Great Lent). The Kontakion to Saint Theodore, who suffered martyrdom by fire, reminds us that he also had faith as his breastplate (see I Thessalonians 5:8).