Rationalism

Rationalism, also known as the rationalist movement, is a philosophical doctrine that asserts that the truth can best be discovered by reason and factual analysis, rather than faith, dogma or religious teaching. Rationalism has some similarities in ideology and intent to humanism, secular humanism, and atheism, in that it aims to provide a framework for social and philosophical discourse outside of religious or supernatural beliefs; however, rationalism differs from both of these, in that:

As its name suggests, humanism is centered on the dignity and worth of people. While rationalism is a key component of humanism, there is also a strong ethical component in humanism that rationalism does not require. As a result, being a rationalist does not necessarily mean being a humanist.

Atheism, a disbelief or lack of belief in God, can be on any basis, or none at all, so it doesn't require rationalism. Furthermore, rationalism does not, in itself, affirm or deny atheism, although it does reject any belief based on faith alone. Historically, many rationalists were not atheists. Presumably, people who are rationalists today generally do not believe that theism can be rationally justified, because modern-day rationalism is strongly correlated with atheism.

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heresy

Heresy, according to the Oxford English dictionary, is a "theological or religious opinion or doctrine maintained in opposition, or held to be contrary, to the 'Catholic' or Orthodox doctrine of the Christian church, or, by extension, to that of any church, creed, or religious system, considered as orthodox. by extension, [heresy is an] opinion or doctrine in philosophy, politics, science, art, etc., at variance with those generally accepted as authoritative."

Urgent concerns with the uniformity of belief and practice have characterized Christianity from the outset.

The process of establishing orthodox Christianity was set in full swing when Paul wrote the epistles that comprise a large part of the New Testament.

On many occasions in Paul's epistles (see also the letters of Paul), he defends his own apostleship, and urges Christians in various places to beware of false teachers, or of anything contrary to what was handed to them by him. The epistles of John and Jude also warn of false teachers, as does the writer of the book of Revelation.

In the middle of the 2nd century, three unorthodox groups of Christians adhered to a range of doctrines that divided the Christian communities of Rome: the teacher Marcion, the pentecostal outpourings of ecstatic Christian prophets of a continuing revelation, in a movement that was called "Montanism" because it had been initiated by Montanus and his female disciples, and the Gnostic teachings of Valentinus.

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