Athanasius of Alexandria

What the apostles received, they passed on without change, so that the doctrine of the mysteries (the sacraments) and Christ would remain correct. The divine Word—the Son of God—wants us to be their (the apostles') disciples. It is appropriate for them to be our teachers, and it is necessary for us to submit to their teaching alone. Only from them and from those who have faithfully taught their doctrine do we get, as Paul writes, "faithful words, worthy of complete acceptance." With them we are back to ground level, because they did not become disciples as a result of what they heard from others. Rather, they were eyewitnesses and servants of God the Word, and they handed down what they heard directly from him.