“Only from them [the apostles] and those who have faithfully taught their doctrine do we get, as Paul writes, “faithful words, worthy of full acceptance (1 Timothy 1:15a).”
Athanasius (c.293-373) was one of the Four Doctors of the Eastern Church and Bishop of Alexandria. He was known for battling against heresies. This quote comes from Festal Letters 2.7. ARL 65. ACCS.1T.143.