Most of the Fathers of the Church I am aware of are the ones quoted in Catholic Prayer books or books on theology. I always assumed the Fathers of the Church would also have to be declared Saints. Guess I'm wrong. Is there a criteria for determining who is and isn't? I would think they all had to be from the 6th century or earlier and of course writers, teachers, theologians and probably priests, bishops or monks.
Good question, I would like to know myself. :) One thing I'm pretty sure about is that the Orthodox, at least, consider some to be Fathers who are much later than the 6th century. One example would be +Gregory Palamas. But then, don't quote me. :) I've looked for lists, but haven't found anything authoritative-looking yet. Apparently there is more than one type of Church Father, so I'm trying to figure that out too.
That is a good question. You can read the church fathers here. I've seen St. Anselm referred to (somewhere) as a Church father but he lived much later than the 6th century. This is a rather confusing issue in my mind.
I would agree with you that I believe the true church fathers lived from the 6th century and earlier. I wouldn't be so quick to dismiss their writings if they were not "Saints" simply because there is much information to be gleaned from their writings. The Catholic Church even admits that Tertullian doctrine and writings for the most part were good although he was at odds with the Church. Saint or not, all their writings do not raise to the same level as scripture according to Church teaching.