A while back I did a post quoting from well known apologists throughout history that have advocated inclusivism (see here). The list demonstrated that inclusivism has been held by orthodox Christians since the time of the church fathers. I have updated that post to include some relevant quotes from Luther, Zwingli, and Arminius.
Inclusivists believe the only way to be saved is through Jesus Christ. Since Jesus died for everyone, inclusivists are also hopeful that some can be justified through Christ without explicit or complete knowledge of who He is. Inclusivists argue that unless salvation is universally accessible, it is meaningless to speak of Christ’s atonement being for all people.
Among the Protestant reformers, Zwingli was the most vocal inclusivist. He sparred with Calvin over the issue (Calvin was an exclusivist). Zwingli proposed that pre-Christian Greeks like Socrates would be saved, as well as others.
“Then you may hope to see [in heaven] the whole company and assemblage of all the saints, the wise, the faithful, brave, and good who have lived since the world began. Here you will see the two Adams, the redeemed and the redeemer, Abel, Enoch, Noah, Abraham, Isaac, Jacob, Judah, Moses, Joshua, Gideon, Samuel, Phineas, Elijah, Elisha, Isaiah, and the Virgin Mother of God of whom he prophesied, David, Hezekiah, Josiah, the Baptist, Peter, Paul; here too, Hercules, Theseus, Socrates, Aristides, Antigonus, Numa, Camillus, the Catos and Scipios; here Louis the Pious, and your predecessors, the Louis, Philips, Pepins, and all your ancestors who have gone hence in faith. In short there has not been a good man and will not be a holy heart or faithful soul from the beginning of the world to the end thereof that you will not see in heaven with God.” (Zwingli, Exposition of the Christian Faith, page 16)
Although less outspoken than Zwingli (at least on this issue), there is evidence that Luther also was an inclusivist. In his commentary on Romans, Luther proposed that the unevangelized can be forgiven by God by responding to Him in the best way that they understand, that God can save them though His prevenient grace, and that God gives forbearance to the ignorant.
“Whoever fulfills the Law is in Christ, and he receives grace because as much as he is able he has prepared himself for it. Original sin God could forgive them [the unevangelized] (even though they may not have recognized it and confessed it) on account of some act of humility towards God as the highest being that they know. Neither were they bound to the Gospel and to Christ as specifically recognized, as the Jews were not either. Or one can say that all people of this type have been given so much light and grace by an act of prevenient mercy of God as is sufficient for their salvation in their situation, as in the case of Job, Naaman, Jethro, and others.”
“They have therefore fulfilled the Law. Whatever was lacking (and for this lack they are excused on account of their invincible ignorance) God in His forbearance without doubt supplied so that it might be made perfect through Christ in the future. This is not different from what He did for the children who were uncircumcised and killed for His sake (cf. Matt. 2:16). He does the same thing today for our children.” (Luther, commentary on Romans, see Romans 2:10)
It’s also evident that Arminius was an inclusivist. He didn’t write too much about the topic – no doubt because the Supralapsarian Calvinists were looking for reasons to have his head. However, he held that God saves some by the internal revelation of the Spirit (without the intervention of human missionaries). He also alluded to an even greater view of God’s mercy, but was unwilling to advance that view in writing.
“The ordinary means and instrument of conversation is the preaching of the Divine word by mortal men, to which therefore all persons are bound; but the Holy Spirit has not so bound himself to this method, as to be unable to operate in an extraordinary way, without the intervention of human aid, when it seemeth good to Himself….this very common sentence obtains our high approval…What peril or error can there be in any man saying, “God converts great numbers of persons, (that is, very many) by the internal revelation of the Holy Spirit or by the ministry of angels; “provided it be at the same time stated, that no one is converted except by this very word, and by the meaning of this word, which God sends by men to those communities or nations whom He hath purposed to unite to himself. The objectors will perhaps reply, “It is to be feared, that, if a nation of those who have been outwardly called should believe this, rejecting external preaching, they would expect such an internal revelation or the address of an angel.” Truly, this would be as unnatural a subject of fear, as that a man would be unwilling to taste of the bread which was laid before him, because he understands, “Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God.” But I desist; lest, while instituting an examination into the causes of this fear, I should proceed much further, and arrive at a point to which our brethren might be unwilling for me on this occasion to advance. A word is sufficient for the wise.” (The Works of James Arminius, Volume 1, Article 8)