The saint for today is Saint Ignatius of Antioch:
Ignatius of Antioch (Ancient Greek: Ἰγνάτιος Ἀντιοχείας, also known as Theophorus from Greek Θεοφόρος “God-bearer”) ((c. 35 or 50) – (from 98 to 117)) was among the Apostolic Fathers, was the third Bishop of Antioch, and was a student of John the Apostle. En route to Rome, where according to Christian tradition he met his martyrdom by being fed to wild beasts, he wrote a series of letters which have been preserved as an example of very early Christian theology. Important topics addressed in these letters include ecclesiology, the sacraments, and the role of bishops.
Saint Ignatius is an extraordinarily fascinating individual. Our understanding of him is greatly helped by the fact that many of his writings have survived to the present day. Unfortunately a number of spurious writings were also attributed to him as well. Still, his writing provides a valuable glimpse into the life, history and theology of the early Church. Three things that I found especially interesting:
1) He was one of the earliest teachers of the dualistic nature of Jesus Christ as both God and Man.
2) It seems that he was an early advocate of the doctrine of transubstantiation, given his statements on the Eucharist being the flesh of Christ.
3) He is also known or believed to be the first person to use the Greek word katholikos to describe the church. The word means universal or complete. Here is a bit from the wiki:
It is from the word katholikos (“according to the whole”) that the word catholic comes. When Ignatius wrote the Letter to the Smyrnaeans in about the year 107 and used the word catholic, he used it as if it were a word already in use to describe the Church. This has led many scholars to conclude that the appellation Catholic Church with its ecclesial connotation may have been in use as early as the last quarter of the 1st century.
The universality of the church thus seems to have been a very early development, dating perhaps even to the Apostolic period.
I encourage everyone to read the whole article at wikipedia, as there is a great deal to absorb there that is worth reading.