The word heresy comes from haeresis, a Latin transliteration of the Greek word meaning choosing, choice, course of action, or in an extended sense school of thought. Irenaeus (b. between the years 115 – 125 according to some, or 130 – 142, d. 202) defined heresy as deviation from the standard of sound doctrine.
Epistle to Titus
The Pauline epistles, Epistles of Paul, or Letters of Paul, are the thirteen New Testament books which have the name Paul (??????) as the first word, hence claiming authorship by Paul the Apostle. Among these letters are some of the earliest extant Christian documents. They provide an insight into the beliefs and controversies of formative Christianity and, as part of the canon of the New Testament, they have also been, and continue to be, foundational to Christian theology and ethics.
The history of early Christianity bridges over the period from the death of Jesus Christ and birth of the Apostolic Age in about the year 30 to the First Council of Nicaea in 325.