Reformed Church Distinctive: TULIP
In the history of the Reformed Church, errors of various kinds have crept into in an attempt to subvert the faith. One such error was Arminianism, which was condemned at the Synod of Dort in 1618-1619. Due to the international (for its time) scope of the Synod, this Synod approximates an ecumenical council to a large extent, and therefore to the degree that it is biblical, which we think it is, it is binding on the Reformed churches and tradition.
Arminianism is the theological system that came out of the teachings of Jacobus Arminius (1560-1609), a Dutch Reformed minister in the late 16th and early 17th centuries. Arminius professed to hold to the Reformed doctrines and was at one time even a professor at the theological faculty of Leiden University, training pastors for the Dutch Reformed church. But things were not as they seem. Arminius' students began to profess and teach doctrines contrary to the Reformed faith, and they ascribe their new teachings to Arminius himself. Arminius' followers were called the Remonstrants because they remonstrated against what they see as unbiblical teachings, and wanted the Dutch Reformed church to amend its standards to tolerate Arminius' teachings.
Due to social and political considerations, it was not until 1618 that a synod was able to assemble to address the Remonstrants. In order to get more counsel, delegates from the various Reformed churches were invited to participate in the deliberations of the Synod at Dordt, and most of them came with a few exceptions (e.g. the Reformed church in France could not send delegates under the threat of expulsion from the nation). At the synod, Arminianism was examined and condemned as false teaching that "summon back the Pelagian error" (Canons of Dordt, Second Point of Doctrine, Rejection of Errors 3). Needless to say, the Remonstrants were ejected from the Dutch Reformed church after the council.
A major distinctive of Reformed churches, and what ought to be the case in churches that have historical roots in the Reformed tradition (Anglican, Methodist), is the rejection of Arminianism. Now of course, there is not one single type of Arminianism. That is why Arminianism is not necessarily a damnable heresy. But Classical Remonstrant Arminianism is heresy. In fact, church history bore out this judgment in the further apostasy of one of the Remonstrants Conrad Vorstius into Socinianism, and many Remonstrants later became Rationalists.
The Canons of Dordt therefore has acquired a quasi-ecumenical status in the Reformed tradition. Calvinism, as expressed in the acrostic TULIP: Total Depravity, Unconditional Election, Limited Atonement, Irresistible Grace, Perseverance of the Saints, is part of the Reformed faith. All Reformed are Calvinists, although Calvinists may not be Reformed. To deny Calvinism is to deny the Reformed faith, and thus to put oneself in danger of further error leading away from the Christian faith.
Total Depravity teaches that all humans are depraved in every aspect of their being. It does not teach that all people are as wicked as they could be. Rather, the focus of Total Depravity is that there is not any one aspect of mankind that is not tainted by sin. Even the will of Man is affected by sin so that nobody can choose God of his own free will, not because he cannot do so if he wants to, but that he is unable to want to do so (CD, 3/4).
The Remonstrants claim to believe in Total Depravity, which is why the third and fourth articles of doctrine are combined in the Canons of Dordt, to show that they actually do not hold to Total Depravity. In the Remonstrant system, man is "totally depraved" but his will is not depraved enough to choose God, whether that comes about naturally or by some prevenient grace. But in Reformed theology, Total Depravity implies that humans by our own nature cannot choose God (Rom. 3:10-11). Left to ourselves, no one would choose to believe in the true God, and therefore it is only God that can save us.
Unconditional election teaches that God elects whom He wants to save, and He elects those whom He saves apart from any condition whatsoever, or any supposed virtue, in sinners. In other words, election unto salvation is not for some "deserving" individuals, but that God elects and saves those whom He wills, based on nothing in the sinner.
This is opposed to the Arminian idea that God elects whom to save based upon foreseen faith. In this view, God sees down the hallway of time so to speak, and then saves those who puts their faith in Him. Election unto salvation according to Arminianism is conditional upon faith, but that is not taught in Scripture, which makes election dependent purely on God's good pleasure (Eph. 1:11). God will have compassion on those whom He will have compassion, and He will harden those He wants to harden (Rom. 9:14-18). Out of the same lump of clay, God will destine one for salvation and another for damnation (Rom. 9:21), and there is no injustice to God in doing that. For "who are you, O Man, to answer back to God?" (Rom. 4:20).
Limited or Definite Atonement
Limited or Definite Atonement is the teaching that Jesus came to save a definite people. This is opposed to the Arminian teaching that Jesus came to die for all people without exception (thus "limited" as a contrast to the Remonstrants' "unlimited" atonement). Calvinists note that the use of the words "all" and "world" need to be qualified by their surrounding contexts, for surely "all the world" in Luke 2:1 means all of the Roman world, not the entire world. Therefore, verses that are claimed to teach an atonement for "all" and for "the world" need to be likewise qualified and interpreted.
Scripture is clear that Jesus came to die for His sheep (Jn. 10:15), and not everyone is of His sheep (Jn. 10:26). All the Father gives to the Son will be saved (Jn 6:37). Jesus came to die for His Bride, not for anyone else. There is a singular intention in all of God's actions in salvation (Eph. 1:9-10), including Jesus' death on the Cross to atone for our sins.